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28

W&T

RS232 Multi Computer Adapter

Serial format

Baud rate, number of data bits and any parity bit which may
be used can be configured separately for each port on the
T-switch, so that the format can be adapted to any connected
terminal device.

Handshake procedure

All serial ports on the T-switch can be set to hardware
handshake or XON/XOFF handshake independently of each
other. Operating the T-switch with no handshake is not
recommended.

When one of the internal buffers in the T-switch is nearly
filled with data, an XOFF code (13H) is output on the
corresponding port and for the next received character the
hardware handshake output is set to ‚Block‘ (negative level).
Once the buffer has been emptied again, an XON code (11H)
is output and the hardware handshake output is set to
‚Enable‘ (positive level).

If the T-switch receives an XOFF code or detects a block level
(negative level) on the hardware handshake input, it stops
sending data on the corresponding port no later than one
byte after this state is detected. If the T-switch receives an
XON code or detects an enable level (positive level) on the
hardware handshake input, it resumes sending data.

The XON and XOFF codes are used only for the handshake;
these codes are not data and are also not allowed to be
contained in the user data. If a hardware handshake is used
however and the T-switch is correspondingly configured, the
XON and XOFF codes are treated as normal data.

When hardware handshake inputs are open or improperly
wired, the T-switch may send no data on the affected port.
If you use only software handshake and configure the
T-switch accordingly, this problem will of course not occur.

Summary of Contents for RS232

Page 1: ...19 W T RS232 Multi Computer Adapter Subject to error and alteration W T Manual RS232 Multi Computer Adapter Release 1 2 Model 85603...

Page 2: ...ion Please inform us of any error or misunderstanding you come about so we can identify and eliminate it as soon as possible Carry out your work on or with W T products only to the extent that they ar...

Page 3: ...red without requiring manual intervention to switch them automatic se lection is on the first come first served principle The interfaces of the Multi Computer Adapter can be configured independently o...

Page 4: ...4 Display and control elements 26 Configuring the serial ports 27 Serial format 28 Handshake procedure 28 Setting the format DIL switches 29 Modes 30 Manual mode 30 Standard mode 30 Transparent mode 3...

Page 5: ...panel of the switch indicate which of the two input channels is currently active Supply voltage The supply voltage for the T switch is provided by an integrated switched mode power supply This feature...

Page 6: ...geous to screw a SUB D plug with body to one port on the T switch and use the attached plug to assist in pulling off the housing cover Wiring assignments The RS232 ports A and B are implemented as SUB...

Page 7: ...put 3 data in TxD input 4 handshake in DTR input 5 signal GND GND GND 6 handshake out DSR output 7 not connected RTS input 8 handshake out CTS output 9 always off RI output RS232 output Port C with DT...

Page 8: ...parity or framing errors in running data traffic and can only be cleared explicitly by pressing the Clear key The Clear key resets the T switch and deletes all internal data and error memories Pressi...

Page 9: ...erface modules to convert the interface type within the device Especially when larger quantities are involved changing over the T switch with other interface modules represents an economical alternati...

Page 10: ...is output and the hardware handshake output is set to Enable positive level If the T switch receives an XOFF code or detects a block level negative level on the hardware handshake input it stops send...

Page 11: ...vidual switches can be seen in the following tables handshake S1 data bit S6 hardware handshake off 7 data bit off software handshake ON 8 data bit ON parity S7 S8 no parity X off odd parity off ON ev...

Page 12: ...rectional connection between Port A and Port C or between Port B and Port C Pressing the key below LED A opens path Port A Port C whereas pressing the key below LED B activates the path Port B Port C...

Page 13: ...e input from being activated in the middle of a protocol block and thereby a fragmented data record from reaching the receiver In this mode the Multi Computer Adapter supports only the two data lines...

Page 14: ...up an RS232 port is often accompanied by difficulties since both the pin assignments as well as the transmission parameters need to agree in order to enable errorless data transmission The RS232 Multi...

Page 15: ...output Hold down the Dump key and then connect the T switch to its power supply After releasing the key the port set on the DIL switches SW4 3 and SW4 4 generates the following output PU 40 6000 SI 0...

Page 16: ...ion cable PC 2 RS232 COM port PC 1 RS232 COM port Port A 9 pin female connector Port B 9 pin female connector RS232 Multi Computer Adapter 85603 Port C 9 pin male connector Peripheral device with DTE...

Page 17: ...andshake Optional hardware or XON XOFF handshake Supported signals RxD TxD CTS DTR Operating modes Standard and transparent mode Switchover time Settable switchover time of 5 15 30 120 seconds other v...

Page 18: ...36 W T RS232 Multi Computer Adapter Declaration of Conformity...

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