10-410.3 Modbus (RTU Mode) for Temperature Control Unit,etcPLC model selectionDevice setting: Start No. *****0Select "Modbus (RTU mode | Temperature control unit, etc)Overview of communicationOnly function codes "03" and "06" which are the command to read/write the contents of the holdingregisters are used. The function code "03" is a message to enable the contents of multiple holdingregisters to be read, however, GT reads the number of holding registers by 1 word.For outputting bit, read the value of the holding register to be output and change the bit before writing.Usable devicesBit/Word Device No.Bit Device Holding register 400000.0-465535.FWord Device Holding Register 400000-465535Communication Parameters SettingsThe example of communication settings of GT and a device such as temperature control unit is shownbelow.Setting Values for GT (Set in the configuration setting of GTWIN.)Item SettingPLC Unit No. 1Baud Rate 19200bpsLength of Bits 8Stop Bits 1Parity EvenSetting Values for Temperature control unit, etcItem SettingStation Address 1Mode RTUBaud Rate 19200bpsLength of Bits 8Stop Bits 1Parity EvenPrecautions when making communication settingsWhen connecting the GT via RS485, set the transmission delay in GT Configuration to 5 ms or more.(The appropriate values vary according to equipment to be connected. Check with actual equipment.)
