Hitachi MICRO-EHV+ Applications Manual page 169

9. Modbus-RTU master FC 05 and FC 15
When function code 05 (Write Single Coil) or 15 (Write Multiple Coils) is used in Modbus-RTU master, default value
in I/O mapping table does not work. Be sure to write value (TRUE or FALSE) in user program.
10. Modbus-TCP slave
If MICRO-EHV+ is reset (Reset warm/cold operation) during Modbus-TCP communication, it takes about 60 seconds
to restart communication due to limitation of TCP protocol stack.
If Modbus client does not respond properly to closing command from MICRO-EHV+ with reset operation, status
indication in EHV-CODESYS shows green circle although communication stops. The indication turns to red triangle
60 seconds after the reset operation, but actual communication status is ready-to-start.
11. CAA_NetBaseService library
Client function of CAA_NetBaseService library does not work in MICRO-EHV+ CPU ROM VER.3.5.3.41 or older.
[only for EHV-CODESYS V3.5 SP3 Patch 6]
A1– 3
Appendix