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EVO/
™ECM-Modbus RTU
Series 2
Page 14
Application Guide
©2020 All Rights Reserved
Evolution Controls Inc.
San Diego, CA USA
Configuration Flags Nibble
Flags may be set or cleared to modify the behavior of the EVO/ECM-Modbus RTU. The upper
nibble of the lower byte of register 14 contains 4 flags.
Communication Timeout Flag
(Register 14, Bit 4)
If the EVO/ECM-Modbus RTU loses communication, it will continue to operate at the last values
set by the Modbus Master. If the communications timeout flag is set (1), and the RTU does not
receive a valid communication for 3 minutes, a reset will occur, and the default values will be
loaded into their respective dynamic registers.
Reserve Flag
(Register 14, Bit 5)
Bit 5 is reserved for future use.
Group 1 Reply Flag
(Register 14, Bit 6)
Group addressing allows a write register (16) or write multiple registers (06) command to be
issued to a group of EVO/ECM-Modbus RTUs. None of these RTUs issue a reply to the Modbus
Master, since all RTUs in the group would try to reply at the same time. Some Modbus Masters
can be configured so they do not need a reply. Others will generate a communication error if they
do not receive a reply.
When the Group 1 Flag is set (1), this RTU will provide a reply when the Group 1 address is polled.
Only set this flag for one of the RTUs in the group.
Group 2 Reply Flag
(Register 14, Bit 7)
Group addressing allows a write register (16) or write multiple registers (06) command to be
issued to a group of EVO/ECM-Modbus RTUs. None of these RTUs issue a reply to the Modbus
Master, since all RTUs in the group would try to reply at the same time. Some Modbus Masters
can be configured so they do not need a reply. Others will generate a communications error if
they do not receive a reply.
When the Group 2 Flag is set (1), this RTU will provide a reply when the Group 2 address is polled.
Only set this flag for one of the RTUs in the group.
