Yokogawa 212 Heat Calculator - Manual (Page 33)

4. COMMUNICATIONS
Three modes of communications are provided:
1. Meter-bus.
2. Infra-red Communications link using M-Bus protocol.
3. RS485 with Modbus RTU protocol.
Terminals 24 and 25 provide a connection for both the Meter-bus and the RS485.
Links on the main board determine which interface is selected as follows:
These links are accessible by removing the front panel as detailed in section 7.2
and the link positions are as shown in the drawing in section 7.3. Links are
made via small black caps which fit over the connecting posts, thereby creating a
link.
Communications 31
B A
Meter-bus
Link 4
Link 5
RS485
Link 4
Link 5