Honeywell HC900 User Manual page 73

Example
Query: Read Signal Tags 3 and 4 from HC900 at address 1 using Function Code 3 (hex codes).
TCP:
00 03
RTU:
01 03
Response: from HC900 where Signal Tag 3 = 100.0 and Signal Tag 4 = 55.32
TCP:
00 03
RTU:
01 03
Revision 13
April 2017
20 04 00 04
20 04 00 04
08 42 C8 00
08 42 C8 00
HC900 Process Controller Communications User Guide
Parameters accessible with Function Code 03, 06,10h
CRC CRC
00 42 5D
00 42 5D
Signal Tags
47 AE
47 AE CRC CRC
65