Evolution Controls EVO/ECM-Modbus, Application Manual

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2020
EVO/
™ECM-Modbus RTU
Series 2 Page 22
Application Guide
©2020 All Rights Reserved
Evolution Controls Inc.
San Diego, CA USA
Read Multiple Coil Registers Command (01)
Address Command
Code
Starting Register Number of Registers Error Check
1-247 01 00 00 00 34 CRC-16
•
Unit, group 1, or group 2 address must be 1-247 (one byte)
•
The command code is 01 (one byte).
•
The starting register is two bytes long. The value must be 00 00 when addressing an EVO/ECM-
Modbus RTU.
•
The number of registers is two bytes in length. The high byte is always 00. The low byte is
always 34 reading all 34 coil registers.
Reply to Modbus Master
Byte Data
Address Command
Code
Count Coil 1-8 Coil 9-16 Coil 17-24 Coil 25-32 Coil 33-40 Error
Check
1-247 01 5 HI LO HI LO HI LO HI LO HI LO CRC-16
•
The byte count is 5 bytes. The more significant bits contain the higher coil variables. Coil 35 to
40 are not used.