8 Digital Communications

 

Digital Communications (or ‘comms’ for short) allows the controller to communicate with a PC or a networked computer system.

 

This product conforms to MODBUS RTU protocol a full description of which can be found on www.modbus.org.

 

Two ports are available:-

 

1. An EIA232 (formerly RS232) configuration port. It is used to download the instrument parameters and to perform manufacturing tests and calibration

2. An EIA485 (formally RS485) port on terminals HD, HE and HF - intended for field communications using, for example, a PC running a SCADA package.

 

The two interfaces cannot operate at the same time.

 

For a further description of digital communications protocols (Modbus RTU) a Communications Manual is available from your supplier.

 

Each parameter has its own unique Modbus address. A list of these is given at the end of this section.