Honeywell HC900 - Manual (Page 60)

52 HC900 Hybrid Controller Communications User Guide Revision 10
12/07
Examples for loop queries using Function Codes 3, 6, 16
Example 1
Query: Read PV, Remote SP, Working SP, Output for Loop 1 from HC900 at slave address 01 using Function
Code 3 (hex codes). This will be accomplished by accessing contiguous registers.
TCP:
00 03 00 40 00 08
RTU:
01 03 00 40 00 08 CRC CRC
Response: where PV=1000.0, Remote SP=1000.0, Working SP=1000.0, Output=50.0
TCP:
00 03 10 44 7A 00 00 44 7A 00 00 44 7A 00 00 42 48 00 00
RTU:
01 03 10 44 7A 00 00 44 7A 00 00 44 7A 00 00 42 48 00 00 CRC CRC
Example 2:
Query: Write a Local Setpoint , (address 006A) to 100.0 for loop 1 at HC900 at slave address 01 using Function
Code 16 (10 hex). Function code 16 is used for presetting multiple registers. Registers are addressed
starting at zero: Register 1 is addressed as 0.
TCP:
00 10 00 6A 00 02 04 42 C8 00 00
RTU:
01 10 00 6A 00 02 04 42 C8 00 00 CRC CRC
Response: from preset of LSP#1, address 006A to 100.0.
TCP:
00 10 00 6A 00 02
RTU:
01 10 00 6A 00 02 CRC CRC
Example 3:
Query: Using Function code 6, set Loop #1 to Auto (register 00FA hex) at controller at slave address 01. This is
a bit-packed single register data type. Registers are addressed starting at 0: Register 1 is addressed as 0.
TCP:
00 06 00 FA 00 01
RTU:
01 06 00 FA 00 01 CRC CRC