Infoton Vista Plus, Technical User'S Manual

Page 1: ...TECHNICAL USER S MANUAL VISTA PLUS ...

Page 2: ... with P l02 Printer Interface Protect Start Protect End I nsert Delete Erase Trans mit and Print commands are modified if issued between Protect Start and Protect End Tab Backtab INTERFACE Maximum data rates are as follows Asynchronous to Internal Timing 820 characters second when in ROLL mode input during rolling action should be limited to 500 charac ters second unless two NULL characters are ad...

Page 3: ...are the same ptli itltr out tc printer is from CRT display Both EIA S 284C ar tGF 20 ma current loop output are available aq O 30 1 0 or 600 characters per second j it g r Polling Module P 301 Allows addressing of individual VISTA PLUS displays on multi dropped line Includes acknowledgment ACK and negative acknowledgment NAK to indi cate terminal status or status of received message Acknowledgment...

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Page 5: ...INFOTON INCORPORATED SECOND AVENUE BURLINGTON MA SACHUSlll 01803 AR A COD 617 272 bfi60 INPOTON TECHNICAL USER S MANUAL VISTA PLUS 00915 28 June 1971 ...

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Page 7: ...hapter 2 introduces th system configurations based upon the VISTA PLUS including clusters of terminals attached to the Message Concentrator and configurations that use polling A description of all the data interfaces which are used in the VISTA PLUS is contained in Chapter 3 Chapter 4 consists of descriptions of peripherals and accessories for the VISTA PLUS that are not described in detail elsewh...

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Page 9: ...Commands Which Do Not Enter Characters Into Memory Control Panel States of the VISTA PLUS Transitions Between States of the VISTA PLUS Priorities Data Transmission Format Messages from the VISTA PLUS Messages to the VISTA PLUS VISTA PLUS SYSTEM CONFIGURATIONS 00915 Single Unpolled VISTA PLUS Details of Polling Dialog Read Poll Write Poll Write Poll with Fast Select VISTA PLUS Terminal Equipped wit...

Page 10: ...nchronous Serial Communication Interface Multispeed 76 1 104 Asynchronous Seria Current Loop Interface TTY Multispeed 78 I 106 Parallel Interface Vi th Line Driver 78 1 107 Synchronous Serial Interface 80 General Description 80 Message Format 80 Details of Interface 81 1 108 Asynchronous Serial Interface with LRC 83 General Descr ption 83 Details of Interface 85 1 109 Asynchronous Serial Interface...

Page 11: ... A 204 Light Pen General Description Operational Details PROGR IING FOR THE VISTA PLUS 00915 Transmission Line Controls Controls in the Data Stream lessage Orientation of VISTA PLUS Programming Considerations for Protected Forms iscellaneous Programming Notes Use of the VISTA PLUS with Time sharing Computers Programming Consideration Related to Data Rates 28 June 1971 88 89 90 91 91 91 92 95 96 96...

Page 12: ...S with P 30l Polling Iodule 8 WRITE Poll Dialog with Optional Fast Select Feature INFOTON VISTA PLUS with P 30l Pollin Module 9 Control Panel of Asynchronous Serial Inter faces 1 103 1 104 and 1 105 10 Current Loop Connections for 1 105 and 1 104 Asynchronous S rial Interface 11 Data Rate vs Cable Length as a Function of Signal Level for INFOTO Current Loop Inter face 1 104 and 1 105 12 Control Pa...

Page 13: ...Code Set 3 VISTA PLUS Code Set with Octal and Hexadecimal Codes 4 Summary of VISTA PLUS Interfaces 5 Outline of VISTA PLUS System Configurations 6 Summary of VISTA PLUS Interfaces 7 Pin Connections for 1 105 and 1 103 Asynchronous Serial Interface 8 Connections for 1 106 Parallel Interface 9 Pin Connections for 1 107 and 1 108 Serial Interfaces 00915 8 June 1971 6 7 9 10 II 40 41 66 73 79 82 ...

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Page 15: ...TANDARD which are teletype compatible terminals that transmit each character as its key is depressed With the VISTA PLUS a computer may send messages to define protected fields the operator may enter and edit data in any unprotected field on the screen prior to block transmission A VISTA PLUS consists of a keyboard cathode ray tube display screen refresh electronics and one of several data communi...

Page 16: ...entrator which allows up to 64 display terminals to be attached to the same line in either a remote or local environment Figure 1 illustrates the possible configurations A more detailed description of the various system configurations is contained in Chapter 2 When the A lOl Message Concentrator is equipped with a P 30l Polling Module with the two character address option then more than 64 VISTA P...

Page 17: ... TIO rOMPUTER Llt JE5 MODE 15 I EQul e 1 1 I I 1 l MI r _ _ r rMO EMI lMOOEMJ r I JWITC ED NETWORK OR DEDICA TED ___ L NE S ____ OEOICA TED LINE _ I 1 r IGlJRE I LOCA L TERMIt JALS NO AODEMS INFOTO l JISTA PLUS STEM CONFIGURATIONS 00915 28 J un e l 7 1 3 ...

Page 18: ...r from the option interface will be displayed The characters presented on the screen should be thought of as an image of the contents of the internal memory of the VISTA PLUS When a character is entered into the memory the image on the screen is automatically updated The details of the method whereby a character is inserted at the proper position of the circulating MOS shift register memory need n...

Page 19: ...yboard Video Generator Control Input Output Sequencer and State Control Data Interface Data Channel Memory Option Interface Optional Device or Accessory FIGURE 2 SYSTEM BLOCK DIAGRAM FOR VISTA PLUS 00915 5 28 June 1971 ...

Page 20: ...ize No inal Character Format 12 Diagonal P4 white characters on dark background Screen easily read without disruptive reflections in 100 foot candle illumination OB wide x 19 high 5 x 7 dot matrix upper case 80 20 8 5 Displayable Character Set 5 x 10 matrix lower case option 64 character ASCII standard Cursor Refresh Rate Memory Power Dimensions Weight 00915 28 June 1971 96 character ASCII with A ...

Page 21: ...Serial Interface Parallel Interface I O Rate 0 to 40 C operating 30 to 70 C storage o to 95 non condensing Current Loop or RS 232C TTL Logic Bit Parallel Demand Response Control 1500 character second parallel up to 820 characters second serial TABLE 1 SPECIFICATIONS OF INFOTON VISTA PLUS 1100915 28 June 1971 7 ...

Page 22: ... in Chapter 2 In the standard VISTA PLUS with the 64 character ASCII set the lower case codes are not generated from the keyboard the upper cas e alphabetic codes are generated when the SHIFT key is not depressed Nevertheless if lower case codes are received through a VISTA PLUS I O interface they will be stored in memory as lower case codes but displayed as upper case When transmitted from the me...

Page 23: ... r 1101 A R I A G E C UR S I I RETURN DOWN I i I I j PROTECT PROTECT END START I 1 t t 1 1111 BLINK BLINK I END START I _ _ I o I U E V F W X Y z I I I t I I I I I G H I J K L M N o U I v W X Y z t i 3 GEN I ADD I The area enclosed by dashed lines is reserved for lower case 1 Reserved for communications not generated or recognized internal to the VISTA PLUS 2 Used as an extension code in certain s...

Page 24: ...ELD ERASE PAGE ERASE CURSOR UP 1 OO _ CARRIAGE CURSOR RETURN DOWN PROTECT r PROTECT END START BLINK BLINK END START k i I i L 1 f I I I 1 T I o _ 1 i oo i M m I L r n rv 1 1 3 GEN o ADD _ i I 1_ 1 Reserved for conununications not generated or recognized internal to the VISTA PLUS 2 Used an an extension code in certain sequences used with A 204 Light Pen 3 General address used only with A lO Messag...

Page 25: ...SET ENQ ACK BELL CURSOR HOME FORWARD TAB NEW LINE LF FIELD ERASE PAGE ERASE CARRIAGE RETURN PROTECT END BLINK END XMIT PAGE PRINT FIELD PRINT PAGE XMIT FIELD DC4 11 REMARKS Start of header Used only in communications START OF TEXT END OF TEXT END OF TRANSMISSION used only in communications I O RESET Internal to VISTA PLUS ENQ Polling Code used only in communications ACKNOWLEDGE Used only in commun...

Page 26: ...ynchronous Idle Character Used only in communication 027 17 Not Used at Present 030 18 ROLL 031 19 CURSOR RIGHT 032 1A CURSOR LEFT Used as extension code in 033 1B ESC certain sequences used with 034 1C CURSOR UP A 204 Light Pen 035 1D CURSOR DOWN 036 IE PROTECT START 037 IF BLINK START 040 20 SPACE 041 21 042 22 043 23 044 24 045 25 046 26 047 27 050 28 051 29 052 2A 053 2B 054 2C 055 2D 056 2E 0...

Page 27: ... CODE CHARACTER 7 BITS 7 BITS NM IE REMARKS 060 30 0 061 31 1 062 32 2 063 33 3 064 34 4 065 35 5 066 36 6 067 37 7 070 38 8 071 39 9 072 3A 073 3B 074 3C 075 3D 076 3E 077 3F 100 40 101 41 A 102 42 B 103 43 C 104 44 D 105 45 E 106 46 F 107 47 G 110 48 H III 49 I 112 4A J 113 4B K 114 4C L 00915 Z8 June 1971 13 ...

Page 28: ...7 BITS NAME REMARKS 115 4D M 116 4E N 117 4F 0 120 50 P 121 51 Q 122 52 R 123 53 S 124 54 T 125 55 U 126 56 V 127 57 W 130 58 X 131 59 y 132 SA t 133 5B 134 SC 135 5D 136 5E t 137 SF 140 60 in 64 character model in 96 character model 141 61 a 142 62 b 143 63 c 144 64 d 145 65 e 146 66 f 147 67 g 150 68 h 151 69 i 00915 28 June 1971 14 ...

Page 29: ... k 1 m n a p q r s t u v w x y z t GEN ADD 15 REMARKS On models with the 96 character option codes 1418 throught 1728 will be displayed as lower case characters On models with the 64 character N CI I set codes 1418 through 1728 will be stored in memory but the characters displayed will be upper case in 64 character mod l in 96 character model in 64 character model I in 96 character model in 64 cha...

Page 30: ...nd until the key is released The keyboard generates the 7 bit ASCII code outputs on seven parallel data lines it also generates a strobe pulse on a separate line to indicate when the data on the data lines is valid The pulse width of the strobe is 200 100 nanoseconds If a single key is depressed then the appropriate code and the strobe are generated If a second coded key is depresse while the firs...

Page 31: ... 00915 z o t o o 28 June 1971 WlJ a zzc 1 I 1 U W 1a ZW t OI 1 U o Wr 1 lJ 1 W CCI lJ WU V WWI l t 9lJ 1 ClJ o a i WIj J z o l n o z t 17 a w I Z uJ 0 a t 0 CO W If J J n I If r W a J 9 LL ...

Page 32: ...t function Afterwards depressing the SHIFT key wil release the shift function In the standard VISTA PLUS with the 64 character ASCII set the keyboard generates the 26 upper case alphabetic characters regardless of whether the SHIFT key is depressed Further more in the standard VISTA PLUS the keys are labeled GJKJCJDJCD always generate the lower character i e 1 and regardless of whether the SHIFT k...

Page 33: ...nter Characters Into Memory The 95 1 ASCII codes from 040 8 through 176 8 are entered into the VISTA PLUS memory either when received from the data line or when their respective keys are depressed With the exception of the SPACE 040 8 all of these codes result in the display of a character on the VISTA screen In addition to the command for SPACE the commands for BLINK START and BLINK END also caus...

Page 34: ...aracter to the first BLINK END character will blink From the keyboard the BLINK START command is initiated by depressing the SHIFT key together with the key labeled R J BLINK END from data line or from keyboard if equipped with the necessary key This command enters a BLINK END code in memory and a blank appears on the screen at the corresponding position Note that a blinking message can be made to...

Page 35: ...creen CURSOR UP from data line or from keyboard by key labeled m The CURSOR UP command moves the cursor one line above its present position If the cursor is in the first line this command will move the cursor to the corresponding position in the bottom line CURS DOWN from data line or from keyboard by key labeled t j The CURSOR DOWN command moves the cursor one line below its present position If t...

Page 36: ...om of the screen When a character is written on the last position of a line the cursor will automatically advance to the first position of the next line When this happens in order to prevent inadvertent double spacing the first NEW LINE command received prior to the receipt of a displaying character will be ignored CARRIAGE RETURN from data line only This command moves the cursor to the first posi...

Page 37: ...r PROTECT START and PROTECT END do not occupy positions in memory The protect logic is implemented by an eighth bit which is set for all characters which enter memory while the VISTA PLUS is in protected input mode The only command which can remove the VISTA PLUS from the protected input mode is PROTECT END Protected data is underlined with dashes when displayed on the screen If desired the VISTA ...

Page 38: ...ASE from data line or from keyboard In the unprotected mode the PAGE ERASE command erases all the un protected characters places the cursor at the home position and establishes the page mode In the protected input mode the PAGE ERASE command erases all data both protected and unprotected The command also homes the cursor and establishes page mode From the keyboard the PAGE ERASE command is initiat...

Page 39: ...d input modes From the keyboard the FORWARD TAB comma _ _i ni tia ted by depressing either of the two keys labeled BTAB I TAB Throughout this manual the command TAB will refer to FORWARD TAB The backward tab always will be explici tly called BACKTAB BACKTAB from keyboard only In the unprotected mode the BACKTAB command moves the cursor backward to the first un protected character to the right of a...

Page 40: ...character just to the left of the first protected character is lost The cursor does not move In the protected input mode all data can be edited as though it were unprotected Thus the operation is as described in 1 above DELETE CHARACTER from keyboard only This command is initiated by depressing the key labeled r LI NE In the unprotected DEL I L__CH RJ mode the effect of the DELETE CHARACTER comman...

Page 41: ...o the right of the cursor or on any line be 10 then the INSERT LInE command creates nulls at the cursor position and the 79 or 39 on the models with a 40 character line following positions If the cursor is not under the first character on a line then the 79 39 nulls will wrap around to the next line The data from the cursor position to the end of the page is moved down one line and the last line o...

Page 42: ... line characters to its right are lost If the cursor is not under the first character on a line then the string of 79 39 characters lost will wrap around the next line The cursor does not move 2 If there is protected data to the right of the cursor or on a line below then the first protected character between the cursor and the end of the page acts as the end of the editing field The insertion of ...

Page 43: ...f the last line at the end of the transmission From the keyboard the TRANSMIT PAGE command is initiated by depress ing either of the two keys labeled r MI Jl L AGE TRANSMIT FIELD from data line or from keyboard In the unprotected mode the TRANSMIT FIELD command backspaces the cursor to the first character of the field and transmits from there to the end of the field The cursor ends up within the f...

Page 44: ...r all data including protected data to the printer PRINT FIELD from data line or from PRINT FIELD switch on control panel This command is available wi th VISTA PLUS displays equipped with the P 102 Printer Interface option In the unprotected mode the PRINT FIELD command backspaces the cursor to the beginning of the field and transfers all the data in the field to the printer At the end of the oper...

Page 45: ... equipped with the 1 107 Synchronous Interface 3 In a VISTA PLUS display with Longitudinal Redundancy Check LRC parity checking i e a display with either the 1 107 or 1 108 Interface parity computation and checking will be terminated upon receipt of the I O RESET code The LRC character for the message will not be checked CONTROL PANEL Figure 4 shows the control panel of the VISTA PLUS Indicator li...

Page 46: ...nitiating either the PRINT FIELD or PRINT PAGE command HORIZ VERT INTENSITY These three control knobs are identical to the horizontal vertical and intensity controls on an ordinary television receiver STATES OF THE VISTA PLUS The INFOTON VISTA PLUS is always in one of six primary states or four intermediate states which are controlled from the data channel and from the keyboard and controls of the...

Page 47: ... 00915 28 June 1971 a a W 0 3 o a z o 0 cJ 0 33 u 0 J I v z w I Z N U I z p 0 E t Z 0 U U p U H q c H ...

Page 48: ...ta The TRANSp IIT state is entered by transmit commands either from the data channel or from the keyboard At the end of a transmission the VISTA PLUS returns to the NULL state PRINT In this state the VISTA PLUS is transmitting data from its memory to an attached printer through the P l02 Printer Interface The PRINT state is entered by the PRINT PAGE or PRINT FIELD commands either from the data cha...

Page 49: ... J 00 a a C U1 CD J t N U1 E T X H F r II r r c Pl HITY MR 1R r H TIr E UT PARITY ERROR OR TIMEOUT VISTA PLUS STATE TRANSITION T RMINt LS WITHOUT POLLING MODULE r IGuRE 5 DIt GRAM I fT I o C i ...

Page 50: ...he format STX TEXT ETX then I O RESET takes priority over any transmit or print codes To emphasize that the VISTA PLUS monitors the data channel for an I O RESET following an STX Figure 5 shows two intermediate states called TRANSMIT STATE STX RECEIVED and PRINT STATE STX RECEIVED Note that a message other than I O RESET sent to the VISTA PLUS will be ignored if the terminal is in the TRANSMIT or ...

Page 51: ...essages transmitted from the VISTA PLUS STX TEXT ETX where STX is the ASCII start of the text code TEXT is the string of characters in the message and ETX is the ASCII end of text code For both XMIT PAGE and XMIT FIELD the following conventions apply to the determination of what is included in the TEXT trans mitted by the VISTA PLUS 00915 1 Each block of mixed spaces and nulls in any combination a...

Page 52: ...ransmitted to the VISTA PLUS is STX TEXT ETX Any message to the VISTA PLUS which is not preceded by a STX character will be ignored If a message is not terminated by an ETX then the VISTA PLUS will remain in the RECEIVE state until a time out period has passed The TEXT sent to the VISTA PLUS can be any message Mlen an XMIT PAGE command is given and TEXT is sent to the computer then the computer ca...

Page 53: ...proceeding to the detailed descriptions it is worthwhile to summarize the contents of Table 5 In all the configurations in Item I each terminal is connected to its own line interface at the computer This mode of operation is common with minicomputers the line interface interprets each character received and interrupts the central processor in order to transfer a character to main memory When modem...

Page 54: ...a stand alone VISTA PLUS with or without the P 301 Polling Module or the P 302 Acknowledgment Modtile In the data line interface of an A lOl Message Concentrator either with or without the P 30l Polling Module In a stand alone VISTA PLUS without the P 301 Polling Module or the P 302 Acknowledg ment Module In a stand alone VISTA PLUS with or without the P 301 Polling Module or the P 302 Acknowledgm...

Page 55: ...With modems not recommended configuration IV A l is preferred 2 Without modems B Current Loop Interface 1 104 1 105 III Single VISTA PLUS with Polling or Acknowledgment Option With Polling Multidropped Operation is Possible A Communication RS 232C Interface 1 103 1 105 1 107 1 108 1 With modems 2 Without modems B Current Loop Interface 1 104 1 105 IV Cluster of VISTA PLUS Terminals Attached to A l...

Page 56: ...Message Concentrator may have a P 301 Polling Module with the two character address option In principle 64 such Message Concentrators each with 64 terminals can be attached to a single line The message formats described in the following sections do not include the synchronizing SYN characters generated by the 1 107 Synchronous Serial Interface The longitudinal redundancy check LRC character used w...

Page 57: ...C In the contention mode the Message Concentrator scans the terminals sequentially at a speed of 1 microsecond per terminal position this rate is adjustable When the M ssage Concentrator encounters a terminal which is contending for ransmission to the computer it stops scanning and allows that terminal to transmit its complete message to the data line Immediately after this message has been transm...

Page 58: ...mputer If the data channel between the Message Concentrator and the computer is half duplex then the Message Concentrator will not be allowed to transmit to the computer when the computer is transmitting to the Message Concentrator The format for messages transmitted through the Message Concentrator to the computer is STX DA TEXT ETX LRC where DA is the device address of the VISTA PLUS at which th...

Page 59: ...lling logic of the INFOTON VISTA PLUS is independent of the type of data line interface used When only one terminal is attached to a line point to point transmission polling is an alternative to contention line discipline Its advantage over the contention mode is that it gives the computer complete control over the incoming stream of messages from a terminal as well as error indications if a messa...

Page 60: ... 64 As an option the P 30l Polling Module may be ordered with a two character device address If this modified polling module is placed in an individual VISTA PLUS then the first character of the address is the ASCII NULL character and the second character is the terminal address If the modified polling module is placed in an A lOl Message Concentrator then the first character is the address of the...

Page 61: ...e polled individually Of course a write poll requires that the second character of the address be the actual address of the terminal If individual VISTA PLUS terminals and VISTA PLUS terminals clustered about A lOl Message Concentrators are attached to the same multidropped line then the P 30l Polling Modules must all be of the same type that is they must all have the same number of address charac...

Page 62: ...lone VISTA PLUS terminals equipped with the P 301 Polling Module and for VISTA PLUS terminals clustered around an A IOI Message Concentrator equipped with the Polling Module Figure 7 illustrates the ordinary write poll Figure 8 shows the write poll dialog for a P 301 Polling Module that has the optional Fast Select feature Both of these diagrams are applicable to stand alone polled terminals and t...

Page 63: ...ress may be one or two characters 3 The terminal responds with a single character I STX S EOT address If attached to an A lOl Message Concentrator the Concentrator address is not included in the response 4 LRC is provided by the 1 107 Synchronous Serial Interface or by the 1 108 Asynchronous Serial Interface S This branch is possible only if the ACK was sent in response to a message that was trans...

Page 64: ...concentrator was broken 3 Send a message to the computer This is the positive response the message waiting for transmission will be sent in the following format STX DA TEXT ETX LRC At the conclusion of the transmission the keyboard of the VISTA PLUS remains locked As will be explained in the next paragraph certain computer responses will unlock the keyboard while others will leave it locked If the...

Page 65: ...CK causes the Message Concentrator to advance to the next terminal that is waiting to transmit The General Poll scan starts at the lowest address and proceeds until every terminal has had one opportunity to transmit An EOT is returned at the end of this sequence 3 Reply with an EOT The transmission with the terminal is terminated The keyboard is not unlocked To reinitiate the path to the terminal ...

Page 66: ...stand alone terminal was placed in the LOCAL mode or if its power was turned off A no response would also occur if the STX character was not received 2 Transmit an ACK This response indicates that the message was received correctly The keyboard is unlocked 3 Transmit a NAK The response means that the message was incorrectly received The keyboard remains locked The reasons for transmitting a NAK ar...

Page 67: ...ample if the terminal is driving an attached printer when the poll is received it will respond with EaT Note that the write poll does override a terminal in ENTER mode The EaT response would also be sent if the data line between a terminal and a concentrator was broken 3 Reply with an ACK This response indicates that the computer may send its message The keyboard is not locked by this response EaT...

Page 68: ...OHCl DA 2 DC4 STX TEXT ETX LRC C4 I I STX EOT TEXT ETX LRC 4 I Responses from Polled VISTA PLUS NO EOT RESPONSE I NO RESPONSE I ACK I I NAK FIGURE 7 WRITE POLL DIALOG INFOTON VISTA PLUS WITH P 30l POLLING MODULE 00915 28 June 1971 54 EOT I 4 ...

Page 69: ... the message was received correctly The keyboard is unlocked The data path between computer and terminal is maintained and the computer may either send another message or terminate communication by sending an EDT 3 Transmit a NAK This response indicates that the message was incorrectly received The keyboard remains locked The reasons for replying with a NAK are a The message contained a parity err...

Page 70: ...n option which may be incorporated in the P 30l Polling Module at the time of manufacture It allows the text of a message to be appended directly to the write poll header This option results in better utilization of communication lines particularly in situations where line turnaround time in modems is significant The initial message from the computer to a terminal is SOH DA DC4 STX TEXT ETX LRC Th...

Page 71: ...TX TEXT ETX LRC I STX EOT TEXT ETX LRC 4 I I I I I I I I I I I I Responses from Polled VISTA PLUS NO I RESPONSE EOT NAK ACK I I FIGURE 8 WRITE POLL DIALOG WITH OPTIONAL FAST SELECT FEATURE INFOTON VISTA PLUS WITH P 30l POLLING MODULE 00915 28 June 1971 57 ...

Page 72: ... WITH P 302 ACKNOWLEDGMENT MODULE General Description In system configurations that are point to point rather than multidropped the complete communication dialog provided by the P 30l Polling Module is not always needed In particular the address recognition logic in polling does not satisfy any basic requirement of a point to point configuration Nevertheless a positive acknowledgment using the ACK...

Page 73: ...ocked It will be unlocked by a successful retransmission of the message or by depression of the I O RESET switch on the VISTA PLUS control panel The following error conditions will cause the terminal to respond with a NAK 1 A character parity error 2 An LRC error checked by 1 107 or 1 108 interfaces 3 A timeout If the character stream stops before the receipt of the ETX code a timeout error will h...

Page 74: ... remains locked 2 Transmit an ACK This response unlocks the keyboard 3 Transmit a message with the format STX TEXT ETX LRC At this point the remainder of the dialog is identical to that explained in the previous section It should be noted that whenever the VISTA PLUS keyboard is unlocked then the terminal will transmit immediately when a Transmit command is issued If there is a requirement to dela...

Page 75: ...terface has odd parity the 1 108 interface uses even parity In addition the 1 107 Synchronous Interface and the 1 108 Asynchronous Serial Interface also check the parity of an entire message by performing a longitudinal redundancy check LRC If after a message has begun a certain interval of time passes without the receipt of a character then a timeout error is detected The length of the timeout pe...

Page 76: ...x 7 dot matrix All forms of errors cause any text which is received after the detection of the error to be ignored If a message contains a detected error tl1en any pending action command contained in the message such as a TRANSMIT or PRINT command will be cancelled With the P 30l Polling Module or P 302 Acknowledgment Module the keyboard of the VISTA PLUS remains locked after the receipt of a mess...

Page 77: ...Concentrator by the computer this code will simply be passed on to the VISTA PLUS and interpreted as a command t place the display in the Roll mode The following chart summarizes the treatment of error in unpolled VISTA PLUS terminals and in VISTA PLUS terminals attached to an unpolled Message Concentrator With the exception of LRC errors which are detected only by the 1 107 and I lOS interface th...

Page 78: ... Cj Cause of Error j y v R 1 v _ _ _ Character Yes Yes Yes Yes Yes Yes Parity Error LRC Yes Yes No Yes Yes Yes Parity Error Timeout Yes Yes No Yes Yes Yes Resetting of the error light and enabling he reception of further text will occur at slightly different times depending on the system configura tion Specifically On stand alone terminals reset action will occur when the NAK is sent In configurat...

Page 79: ...rallel Interface Line Driver may be used with a VISTA PLUS but not with the A lOl Message Concentrator The 1 109 Asynchronous Serial Interface to Message Concentrator is used in a VISTA PLUS which is connected to an A lOl Message Concentrator This is the only application of the 1 109 inter face Any of these interfaces occupies the primary I O port of the VISTA PLUS The standard VISTA PLUS is provi...

Page 80: ... a stand alone VISTA PLUS with or without the P 30l Polling lodule or the P 30 2 Acknowledgment lodule In the data line interface of an A IOI Iessage Concentrator either with or wi thout the P 30 1 Poll ing lodule In a stand alone VISTA PLUS without the P 30l Polling lodule or the P 302 Acknowledg ment Module In a stand alone VISTA PLUS with or without the P 301 Polling Module or the P 302 Acknowl...

Page 81: ...NTERFACE MULTISPEED General Description The Multipurpose Asynchronous Serial Interface is multi purpose in the sense that it provides both a communication inter face compatible with EIA Specification RS 232C and a current loop interface in one printed circuit card The interface provides an exposed panel in the rear of the terminal see Figure 9 on which one may select various modes of operation Spe...

Page 82: ...ROTARY SWITCH CURRENT LOOP MODE SWITCH 00915 4800 EXTl FOX FULL HALF DUPLEX SWITCH FIGURE 9 CONTROL PANEL OF ASYNCHRONOUS SERIAL INTERFACES 1 103 1 104 and I IDS 28 June 1971 68 ...

Page 83: ...d for an RS 232C standard communication interface The code used by the interface is 7 level ASCII Communication is in bit serial character asynchronous mode which is commonly known as START STOP communication The START STOP character format contains one START and one or two STOP bits bracketing the eight seven plus one parity serial data bits The START bit allows the receiving VISTA PLUS to initia...

Page 84: ... standard baud rates are 110 150 300 600 1200 1800 2400 3600 and 4800 These rates are available with both the RS 232C and current loop interfaces of the mUltipurpose asynchronous serial interface an internal crystal clock controls these nine rates The setting EXT 1 on the rotary switch permits the VISTA PLUS to handle data rates other than the nine standard speeds An external free running non sync...

Page 85: ...a 6 foot detachable cable which is used to connect the unit to a computer or appropriate modem On one end of the cable is a MOLEX plug which fits into the rear of the VISTA PLUS reference point 7 Figure 9 The other end of the cable has a 25 pin standard EIA connector which is attached to the customer s modem or computer The pin connections for the MOLEX and EIA connectors are specified in Table 7 ...

Page 86: ...mmunication interface are appropriate for Western Electric 202C switched network modems or 202D private line modems The 1800 baud setting is apprripriate for the Western Electric 202D private line modem The 202C modem operates in asynchronous mode at any speed up to 1200 baud the 202D also an asynchronous modem can operate at any speed up to 1800 baud The 202C modem is typically half duplex but a ...

Page 87: ...Signal Ground EIA Pin No 2 4 5 3 8 20 MOLEX Pin No 1 2 3 4 5 8 No Connec 10 tion to EIA Inter face 7 12 Comments Logical I OFF 6V Logical 0 ON 6V 3000 ohm minimum load impedance Goes high 6V when the terminal is ready to transmit Must be high to allow terminal to send is supplied by a modem Logical 1 OFF 5V to 25V Logical 0 ON 5V to 25V 3000 ohm minimum load impedance Must be high to allow termina...

Page 88: ...in Figure 10 refer to the number of the corresponding pins on a Teletype barrier strip Two wire twisted pair or four wire twisted pair cabling is recommended for half or full duplex operation respectively If the current loop interface is used either in a VISTA PLUS or an A IOI Message Concentrator that is equipped with the P 30l Polling Module then the four wire current loop connection must be use...

Page 89: ...T 00915 28 June 1971 7 6 4 po 3 FULL DUPLEX FOUR WIRE FIGURE 10 IN R NOT USED DATA DATA 7 INPUT t 6 4 3 OUTPUT HALF DUPLEX TWO WIRE CURRENT LOOP CONNECTIONS FOR 1 105 and 1 104 ASYNCHRONOUS SERIAL INTERFACE 75 IN R NOT USED ...

Page 90: ...nd and eliminates the need for parallel I O cabling Further det ils of the current loop operation including sample input and output circuits for constant current operation may be found in INFONOTE 5 71 3 entitled Current Loop Inter face I l03 ASYNCHRONOUS SERIAL COMMUNICATION INTERFACE MULTISPEED The I l03 is a multispeed communication interface which conforms to EIA specification RS 232C it inclu...

Page 91: ... 4 bC O 300 1 r J lie I r 10C 1000 10 000 00 Ct BlE LENGTLJ rr r FIGURE 11 DATA RATE VS CABLE LENGTH AS A FUNCTION OF SIGNAL LEVEL FOR INFOTON CURRENT LOOP INTERFACES 1 104 and I IDS Z T1 o l o Z z o tl tJ o tl l m C tf m o z c m Z c rn OJ c tl C Z Cl l o tf tf I C tf m l 4 tf o co o w tl m o C m en en en en o ...

Page 92: ...h amplifies a differential input signal to levels used by the VISTA PLUS input bus In addition the interface is easily converted to DTL TTL drive and reception for less demanding uses The 1 106 interface will permit parallel data transmission and reception over 1000 foot twisted pair cabling Connections to the interface include 8 wire input 7 bit plus parity 8 wire output and several control lines...

Page 93: ... busy signal Out BST Indicated DATA OUT is valid strobe signal Out BD Data Out LSB Out BDl Data Out Out BD2 Data Out Out DB3 Data Out Out BD4 Data Out Out BD5 Data Out Out DB6 Data Out MSB Out PAR Parity Out Out INITIAL RESET Ext System on pwr ON Out GND Out DTL TTL Ref 2 Reference for T L or DTL Inputs Out BRK Ground going signal when break key is depressed In Parity INH Inhibits Parity Check On ...

Page 94: ... Interface takes its timing from external clocks In typical applications these clocks will be in a modem The interface may be used with synchronous modems compatible with Western Electric 20lA or 20lB The maximum length of cable between the VISTA PLUS and another device depends upon the electrical noise environment but under ordinary conditions the 1 107 synchronous interface will drive 1000 feet ...

Page 95: ...C or longitudinal redundancy check character is formed so that the total number of 1 bits in each of the 7 data bit positions of all the characters starting with the first character after STX and including ETX is even The LRC itself has odd parity as do all the characters The message to be received by the VISTA PLUS has the same format except that only two adjacent SYN characters are required Any ...

Page 96: ...er Clock Signal Ground EIA Pin No 2 4 5 3 8 17 20 15 7 MOLEX Pin No Comments 1 Logical 1 OFF 6V Logical 0 ON 6V 3000 ohm minimum load impedance 2 3 4 5 6 8 9 12 Goes high 6V when the terminal is ready to transmit Must be high to allow terminal to send is supplied by a modem Logical 1 OFF 5V to 25V Logical 0 ON 5V to 25V 3000 ohm minimum load impedance Must be high to allow terminal to recelve is s...

Page 97: ...n this position is compatible with a Western Electric 202D modem In the external position the speed is determined by external clocks This speed setting allows attachment to a Western Electric 20lB modem Although this modem is synchronous the character format is still asynchronous START STOP bits are used for a total of 10 bits per character IIigher speed modems with RS 232C clock levels may also b...

Page 98: ...LRC OUT CIIJ INT aOO 0000 00 00 EIA EXT FIGURE 12 CONTROL PANEL OF 1 108 ASYNCHRONOUS SERIAL INTERFACE WITH LRC 28 June 1971 00915 84 LRC SELECTION ...

Page 99: ...h connects to this plug and which terminates in a 25 pin standard EIA connector In the INT 1200 baud position the 1 108 interface will drive 1000 feet of cable In the EXT position the maximum baud rate depends upon the baud rate Under ordinary electrical noise conditions the external clocked interface will drive 1000 feet of cable at 2400 baud and 500 feet of cable at 4800 baud Table 9 contains th...

Page 100: ...ers per second One character will be received from the data line every 1 600 second After it has been processed by the Message Concentrator in parallel format only 1 960 second is required to transmit the character to the VISTA PLUS In remaining time i e 1 600 1 960 1 1600 sec the line between Message Concentrator and VISTA PLUS waits in the mark condition Even character parity is generated and ch...

Page 101: ...on RS 232C Terminal Busy informs the concentrator whether a message may be sent to the terminal Specifically in response to a polling header it allows the P 30l Polling Module to respond negatively if the terminal is engaged in an I O activity RSVP is a signal from the terminal which notifies the concentrator that a message sent to the terminal contained a parity error This signal is also used by ...

Page 102: ...Module This module is contained on a single printed circuit board which is placed in a designated Accessory Port of the VISTA PLUS A lOl Message Concentrator The Message Concentrator is housed in a desk top cabinet which can contain the power supplies and necessary hardware to connect to as ma y as 64 VISTA PLUS terminals and the communication line The product designated as A lOl contains 8 of the...

Page 103: ...of the integral modems their Western Electric equivalents the transmit levels and the receiver sensitivity are as follows Western Transmit Infoton Electric Levels Receiver Product Equivalent Adj Range Sensitivity P 40l 103A 0 to 12 dbm max 0 to 40 dbm P 402 103F 0 to 12 dbm max 0 to 40 dbm P 403 202C 0 to 12 dbm max 0 to 45 dbm P 404 202D 0 to 12 dbm max 0 to 45 dbm These integral modems like thei...

Page 104: ...n As many as ten displays may hare one printer in a contention mode The first terminal to request service by the printer controls the printer until the print operation is complete or until the I O RESET switch on the controlling terminal is depressed whichever comes first If another terminal requests a print operation while the printer is busy that terminal will indicate I O BUSY until all the wai...

Page 105: ...e cursor reaches the tenth position from the end of a line or when the ASCII BELL code is received by the terminal The maximum rate at which the tone will sound is ten times per second so that a series of BELL codes received at a higher rate will result in a continuous tone The INFOTONE accessory is mounted inside the VISTA PLUS but does not require an Accessory Port A 204 LIGHT PEN General Descri...

Page 106: ... Accessory The switch in the tip of the light pen cartridge is enabled by receipt of the following message STX ESC 140 8 ETX LRC When the pen is enabled its transmit electronics is activated by the detection of a light pulse on the next video frame after the slvitch on the light pen cartridge is depressed The detection of a video input in the next frame after the switch is depressed will be referr...

Page 107: ...i ts for a read poll If the read poll is received when the light pen is not ready to transmit the Polling Module returns an EOT If either the P 301 Polling Module or the P 302 Acknowledgment Module is used this transition occurs after the terminal receives an ACK FIGURE 13 OPERATIONAL DIAGRAM OF A 204 LIGHT PEN ACCESSORY 00915 28 June 1971 9 3 ...

Page 108: ...odule the transmission of the above message must wait for a read poll just as any other terminal would If the P 30l Polling Module or the P 302 Acknowledgment Iodule is used the light pen electronics is inactivated after receipt of an ACK response to the light pen message To enable the light pen to transmit another message the enabling sequence must be retransmitted The light pen switch may be dis...

Page 109: ...vided by common minicomputers In larger computers with a data channel that operates independently of the central processor software for handling input and output to a serial ASCII code device is generally supplied If a serial interface conforming to EIA specification RS 232C is used and if no modems are employed the computer can control messages from the VISTA by controlling the Clear to Send line...

Page 110: ...tion is used then the program must insert the proper addresses in the polling sequence In addition if a general poll is sent to a Message Concentrator then the program must interpret the address of a terminal which responds to the poll CONTROLS IN THE DATA STREAM The commands PRINT FIELD PRINT PAGE TRANSMIT FIELD TRANSMIT PAGE and I O RESET are each sent to the VISTA PLUS as single ASCII character...

Page 111: ...cted fields are used by a program to separate different pieces of data The line feed characters inserted at ends of lines are useful in processing data transmitted by the VISTA PLUS When the VISTA PLUS is equipped with the P 30l Polling Module a NAK will cause the retransmission of whatever was previously transmitted The program need not know whether it was a field or page transmission When a TRAN...

Page 112: ...is operated in PAGE mode and the protected fields cont in field identifiers that would be found on a pre printed form For example the words Name Address Telephone Number etc The operator enters the variable data a person s name address and telephone number using the TAB feature and depresses the TRANSMIT PAGE key Figure 14 shows a hypothetical 4 line by 20 character VISTA PLUS screen arrangement w...

Page 113: ...00915 1 5 10 15 20 1 N A M E 2 ADD RES S 3 TEL E P H 0 N E 4 SAMPLE PROTECTED FORM STX PROTECT START PAGE ERASE N A M E 7 SPACES LF A D D R E S S 4 SPACES LF T E L E P H O N E 2 SPACES PROTECT END HOME TAB ETX FIGURE 14 MESSAGE REQUIRED TO GENERATE A SA 1PLE VISTA PLUS FORMAT 28 June 197 99 ...

Page 114: ...SMIT PAGE ETX Immediately after receipt of the transmission from the terminal the computer should respond with the message STX PROTECT END ETX in order to remove the terminal from protected input mode MISCELLANEOUS PROGRAMMING NOTES The full advantages of VISTA PLUS data compression spaces and nulls at the right hand end of a iine are not transmitted are realized when data on the screen are left j...

Page 115: ...puter In particular the timesharing monitor must not take exception to the STX and ETX codes which are part of each message from the VISTA PLUS Since the VISTA PLUS cannot transmit a carriage return code line feed is automatically inserted between lines as a separator software modifications may be required A carriage return may be sent to the VISTA PLUS however it will return the cursor to the beg...

Page 116: ... at a maximum fixed rate of 500 characters second either in parallel or serial mode When TAB or FIELD ERASE commands are used characters can be transferred at a maximum fixed rate of 500 characters second either in parallel or serial mode If one ASCII NULL character is inserted after each TAB or FIELD ERASE command sent to the VISTA PLUS then a message may be transmitted at fixed rate of 760 chara...

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Page 118: ...Infoton INFOTON INCORPORATED SECOND AVENUE BURLINGTON MASS 01803 CF 18846 00915 May 1973 400 ...