RIR Read Input Registers 04 Reads Modbus Input Registers such as
IR30001
FSC Force Single Coil 05 Writes a Modbus Coil such as C0001
PSR Preset Single Register 06 Writes a Modbus Holding Register such
as HR40001
RES Read Exception Status 07 Reads Modbus Exception Status
FMC Force Multiple Coils 15 Writes multiple Modbus Coils such as
C0001
PMR Preset Multiple Registers 16 Writes multiple Modbus Holding
Registers such as HR40001
FSC_E Force Single Coil -
by Exception
05 Same as FSC but initiated by change of
coil data
PSR_E Preset Single Register -
by Exception
06 Same as PSR but initiated by change of
register data
FMC_E Force Multiple Coils -
by Exception
15 Same as FMC but initiated by change of
coil data
PMR_E Preset Multiple Registersby Exception

RIR读取输入寄存器04读取Modbus输入寄存器，例如
IR30001
FSC强制单线圈05写入Modbus线圈，如C0001
PSR预置单寄存器06写入Modbus保持寄存器，如
as HR40001
RES读取异常状态07读取Modbus异常状态
FMC强制多线圈15写入多个Modbus线圈，例如
C0001
PMR预置多个寄存器16写入多个Modbus保持
寄存器，如HR40001
FSC_E力单线圈-
例外
05与FSC相同，但由
线圈数据
PSR_E预置单寄存器-
例外
06与PSR相同，但由
寄存器数据
FMC_E强制多线圈-
例外
15与FMC相同，但由变更
线圈数据
PMR_E预设多个异常寄存器