Honeywell CIU 888 - Page 36

Appendix A - GPU Communication Protocol
Protocol Manual - CIU Emulation Part No.: 4417589_Rev13
A- 2 CIU 888
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A.2.1 CIU individual command record
This command is executed in the addressed CIU, which sends back an
answer record.
A.2.2 Instrument individual command record
The CIU will pass on these records (without the CIU address) to any
connected field instrument.
REMARK: The value referring to the CIU address (i.e. ‘N’) will not be part of the GPU
commands in case of TCP/IP communication.
STX N TOI TOR ETX BCC
Item Position(s) Description
STX 1 Start of Text Character (= Start of transmission)
N 2 CIU address (0-9)
TOI 3 R CIU-GPU version
TOR 4 X Send identify record
ETX 5 End of Text Character (End of transmission)
BCC 11 Block Check Character
STX N nn TOI TOR ETX BCC
Field Position(s) Description
STX 1 Start of Text Character (Start of transmission)
N 2 CIU address (0-9)
nn 3, 4 Instrument address (00-99)
TOI 5 Type of Instrument:
 B = 811, 854, 873 instrument with GPU protocol
and instruments with Gauge type B
 C = Instruments with Gauge type C
 E = 811 instrument with external alarms and
instruments with Gauge type E
 @ = Any type
TOR 6 Type of Record
See the Protocol Manual of the related field instrument
for more information.
ETX 7 End of Text Character (End of transmission)
BCC 8 Block Check Character