GE Industrial Solutions MX150_MX250 Modbus Network Card - Manual (Page 23)

■ ■ GE Zenith Controls 21 ■ ■ MX150/MX250 Series Modbus Network Card (71R-2200)
Appendix G
(cont’d)
Modbus Protocol Illustration
(cont’d)
Response
The response from the slave is an echo of the slave
address, function code, starting address and number
of coils forced.
Slave
Address
09h
Figure G10 – Write Multiple Coils Response Message
Function
Code
Starting
Address
High Order
Starting
Address
Low Order
Number
of Coils
High
Order
Number
of Coils
Low
Order
Error
Check Field
( LRC or
CRC )
0Fh 00h 28h 00h 10h —
Write Multiple Holding Registers (Function Code 16)
Presets values into a sequence of holding registers.
Query
The following is an example to preset two registers
starting at 40034 (
W -Time) to 9 hex (9 seconds) and 40035
( W 3-time) to 32 hex (50 seconds), in slave device 17.
Slave
Address
11h
Figure G11 – Write Multiple Registers Query Message
Function
Code
10h
Starting
Address
High
Order
00h
Starting
Address
Low
Order
21h
Number
of Regs
High
Order
00h
Number
of Regs
Low
Order
02h
Byte
Count
04h
Data
High
Order
00h
Data
Low
Order
09h
Data
High
Order
00h
Data
Low
Order
32h
Error
Check
Field
(LRC or
CRC )
–
Response
The response from the slave is an echo of the slave
address, function code, starting address and number
of registers to be loaded.
Slave
Address
11h
Figure G12 – Write Multiple Registers Response Message
Function
Code
Starting
Address
High
Order
Starting
Address
Low
Order
Number
of Regs
High
Order
Number
of Regs
Low
Order
Error
Check Field
( LRC or
CRC )
10h 00h 21h 00h 02h —