VAR1 = 107.40.MB_REG_FLOAT_ABCD410
107 is T3-TB panel number
40 is another device connect to T3-TB
410 is the start register address (32 Bit)
BAC_FLOAT_ABCD
BAC_FLOAT_CDAB
BAC_FLOAT_BADC
BAC_FLOAT_DCBA
The links below can give you some ideas
https://forums.temcocontrols.com/t/modbus-poll-vs-temco-modbus-poll-for-external-devices/1009/10
