268XA
Service Manual
2-32
Response Packet Format The response consists of five ASCII characters (plus the
checksum byte), in the form Bxxyy, where B indicates boot software, xx are the two
digits of the major version number, and yy are the two digits of the minor version number
(there is an implicit decimal point between the two). Note that constraining the bytes to
be ASCII characters causes the most significant bit of each character to be a 0, making
the response packet always distinguishable from a NAK.
Set Global Configuration
The Command Packet tells the A/D the following:
•
Measurement Rate, fast, medium, or slow
•
Power Line Frequency, 50 Hz or 60 Hz
•
Scheduled Housekeeping Measurements, Enable or Disable
Action Performed Sets global configuration parameters (instrument measurement rate,
AC power line frequency, and enable or disable housekeeping measurements). The
default state for the inguard is to measure on the fast rate, assuming 60 Hz, and with
scheduled housekeeping measurements enabled. The meaning of “scheduled
housekeeping measurements” depends on the current measurement rate.
Response Packets Returned Always returns a single response packet.
Response Packet Format Returns either an ACK packet or a NAK if the command
arguments are not recognized.
Set Channel Configuration
The Command Packet tells the A/D the following:
Measurement Function V dc, V ac, 2-Wire Ohms, 4-Wire Ohms, Frequency,
Thermocouple, OFF.
Range 90 mV or 300
Ω
, 300 mV or 3 k
Ω
, 3 V or 30 k
Ω
, 30 V or 300 k
Ω
, 50 V (FAI),
150/300 V (PAI), or 3 M
Ω
, 750 mV (reference junction calibration).
The range field is ignored for frequency and thermocouple channels.
Channel Number 0 to 19 (though user sees channel 1 to 20)
Enable Autorange if bit set (ignored for frequency and thermocouple).
Enable Open Thermocouple Detect if bit set.
Checksum Action Performed is configuration of a single channel to the parameters
given. The Response Packets Returned always returns a single response packet. The
Response Packet Format returns an ACK response packet if the channel was successfully
configured; otherwise, it returns a NAK.
Do Housekeeping
The Command Packet tells the A/D to do the following:
•
Do all housekeeping readings if bit set.
•
Do the next housekeeping reading in the schedule if bit set.
•
Prescan: preset the function relays.
Checksum Action Performed is as follows:
•
If the Housekeeping bit is 1, the inguard takes a complete set of housekeeping
readings for the current measurement rate (there is one set for each rate).
Summary of Contents for 2680A
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Page 204: ...268XA Service Manual 7 10 268X FINAL ASSEMBLY alg105f eps Figure 7 1 268XA Final Assembly ...
Page 207: ...Replaceable Parts Parts Lists 7 7 13 2680A DIO alg100f eps Figure 7 3 DIO Module ...
Page 209: ...Replaceable Parts Parts Lists 7 7 15 2680A FAI alg102f eps Figure 7 4 FAI Module ...
Page 211: ...Replaceable Parts Parts Lists 7 7 17 2680A PAI alg103f eps Figure 7 5 PAI Module ...
Page 214: ...268XA Service Manual 8 2 ...
Page 215: ...8 3 8 Schematic Diagrams Figure 8 1 Backplane PCA 2680A 4001 ...
Page 216: ...268XA Service Manual 8 4 Figure 8 1 Backplane PCA cont 2680A 1001 ...
Page 217: ...8 5 8 Schematic Diagrams Figure 8 2 Controller System Power PCA 2680A 4004 ...
Page 223: ...8 11 8 Schematic Diagrams Figure 8 3 Digital I O PCA 2680A 4006 ...
Page 224: ...268XA Service Manual 8 12 Figure 8 3 Digital I O PCA cont 2680A 1006 1 of 3 ...
Page 225: ...8 13 8 Schematic Diagrams Figure 8 3 Digital I O PCA cont 2680A 1006 2 of 3 ...
Page 226: ...268XA Service Manual 8 14 Figure 8 3 Digital I O PCA cont 2680A 1006 3 of 3 ...
Page 227: ...8 15 8 Schematic Diagrams Figure 8 4 Backplane Extender PCA 2680A 4009 ...
Page 228: ...268XA Service Manual 8 16 Figure 8 4 Backplane Extender PCA cont 2680A 1009 ...
Page 229: ...8 17 8 Schematic Diagrams Figure 8 5 Extender PCA 2680A 4010 ...
Page 230: ...268XA Service Manual 8 18 Figure 8 5 Extender PCA cont 2680A 3010 ...
Page 231: ...8 19 8 Schematic Diagrams Figure 8 6 A D Supply Assembly 2680A 4031 ...
Page 232: ...268XA Service Manual 8 20 Figure 8 6 A D Supply Assembly cont 2680 1031 ...
Page 233: ...8 21 8 Schematic Diagrams Figure 8 7 PCMCIA PCA 2680A 4041 ...
Page 234: ...268XA Service Manual 8 22 Figure 8 7 PCMCIA PCA cont 2686 1041 ...
Page 235: ...8 23 8 Schematic Diagrams Figure 8 8 Output PCA 2680A 4062 ...
Page 236: ...268XA Service Manual 8 24 Figure 8 8 Output PCA cont 2680A 1062 ...
Page 237: ...8 25 8 Schematic Diagrams Figure 8 9 A D PFE PCA 2640A 4003 ...
Page 238: ...268XA Service Manual 8 26 Figure 8 9 A D PFE PCA cont 1 of 6 ...
Page 239: ...8 27 8 Schematic Diagrams Figure 8 9 A D PFE PCA cont 2 of 6 ...
Page 240: ...268XA Service Manual 8 28 Figure 8 9 A D PFE PCA cont 2640A 1003 3 of 6 ...
Page 241: ...8 29 8 Schematic Diagrams Figure 8 9 A D PFE PCA cont 2640A 1003 4 of 6 ...
Page 242: ...268XA Service Manual 8 30 Figure 8 9 A D PFE PCA cont 2640A 1003 5 of 6 ...
Page 243: ...8 31 8 Schematic Diagrams Figure 8 9 A D PFE PCA cont 2640A 1003 6 of 6 ...
Page 244: ...268XA Service Manual 8 32 Figure 8 10 A D FFE PCA 2645A 4003 ...
Page 245: ...8 33 8 Schematic Diagrams Figure 8 10 A D FFE PCA cont 2645A 1003 1 of 6 ...
Page 246: ...268XA Service Manual 8 34 Figure 8 10 A D FFE PCA cont 2645A 1003 2 of 6 ...
Page 247: ...8 35 8 Schematic Diagrams Figure 8 10 A D FFE PCA cont 2645A 1003 3 of 6 ...
Page 248: ...268XA Service Manual 8 36 Figure 8 10 A D FFE PCA cont 2645A 1003 4 of 6 ...
Page 249: ...8 37 8 Schematic Diagrams Figure 8 10 A D FFE PCA cont 2645A 1003 5 of 6 ...
Page 250: ...268XA Service Manual 8 38 Figure 8 10 A D FFE PCA cont 700p29_topress zip 2645A 1003 6 of 6 ...
Page 251: ...8 39 8 Schematic Diagrams Figure 8 11 Analog Input Connector PCA 2620A 4004A ...
Page 252: ...268XA Service Manual 8 40 2620A 1004 Figure 8 11 Analog Input Connector PCA cont ...
Page 253: ...8 41 8 Schematic Diagrams Figure 8 12 Display PCA 1 of 1 ...
Page 254: ...268XA Service Manual 8 42 Figure 8 12 Display PCA cont 1 of 1 ...