The PM8TC module is a 8 thermocouple input module. The module uses differential inputs to reduce effects of electrical noise and mains pickup. The thermocouple inputs are isolated from the logic. If inter channel isolation is required then the PM8TCISO should be used.

The thermocouple voltage is read by the module circuitry, linearised and converted to degrees Centigrade. No ranging is required as the module covers the full range as indicated in the table of TC types. The value that is read from the Modbus register is the actual temperature in degrees centigrade to 0.1°C resolution. ie: a value of 3451 corresponds to a temperature of 345.1°C.

The module has built in Cold Junction Compensation. Use must be made of the correct thermocouple extension wire to avoid reading errors.

The thermocouple module can also be configured for a 0 – 50mV input range. The TC Type register must be set to 9 for this option. The value in the register which is read back over the network is 0 – 50,000.

Note: As there is no inter-channel isolation, isolated thermocouples must be used in order to prevent ground loops and reading errors.

PROMUX RS485 (I/O Modules)

PROMUX is an innovative modular I/O system which provides a simple low cost solution for distributed I/O requirements.

The PROMUX system consists of stand-alone Digital and Analog Input and Output modules which are connected together on a RS485 two wire multi-drop network. The modules communicate using the MODBUS RTU protocol.

A 32bit ARM CPU is used in the modules to provide high speed data processing and fast communications turn around times. Multiple baud rates are selectable from 2400 to 115200 baud.

All PROMUX modules plug directly onto an industry standard DIN rail. All modules have a minimum isolation of 1000VAC rms between the field and logic. The modules have been equipped with status led’s which are used to indicate the status of the Inputs or outputs. This visual indication assists with fault finding and diagnostics.