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(0x05) Force (Write)
Single Coil
Thermo Fisher Scientific
The contents of register 10 are shown as the two byte values of 0x02 0x2B.
Then contents of registers 11–13 are 0x00 0x00, 0x00 0x64 and 0x00 0x64
respectively.
The force (write) single coil function simulates the activation of the digital
inputs in the instrument, which triggers the respective action.
This function code is used to set a single action to either ON or OFF. The
request specifies the address of the action to be forced. Actions are
addressed starting at zero. Therefore, action number 1 is addressed as 0.
The requested ON/OFF state is specified by a constant in the request data
field. A value of 0xFF00 requests the action to be ON. A value of 0x0000
requests it to be OFF. All other values are illegal and will not affect the
output. The normal response is an echo of the request, returned after the
state has been written.
Request
Function code
Starting Address
Output Value
Response
Function code
Starting Address
Output Value
Error Response
Function code
Exception code
Here is an example of a request to write Coil 5 ON:
Request
Field Name
Function
Output Address Hi
Output Address Lo
1 Byte
0x05
2 Bytes
0x0000 to maximum allowed by instrument
2 Bytes
0x0000 or 0xFF00
1 Byte
0x05
2 Bytes
0x0000 to maximum allowed by instrument
2 Bytes
0x0000 or 0xFF00
1 Byte
Function code + 0x80
1 Byte
01=Illegal Function, 02=Illegal Address,
03=Illegal Data, 04=Slave Device Failure
(Hex)
05
00
05
MODBUS Protocol
Function Codes
Model 146i Instruction Manual
C-7
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Troubleshooting
