Mitsubishi Electric Procon A1M, Installation Manual

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3. Settings
There is a bank of 8 DIP switches on the Procon A1M PCB labelled as ‘CONFIGURATION’. These switches are used
to configure the Modbus Slave ID and the RS-485 baud rate.
3.1. Modbus Slave ID
Any Modbus Slave ID in the range 1 – 31 can be chosen using switches 1 – 5. The address is set in binary, where the
switch positions have the following values:
Switch number Value when switch is set to ON
1 1
2 2
3 4
4 8
5 16
To get the Slave ID, add together the value for each switch set to ON. For example, to set address 13, set switches 1,
3 and 4 ON (1 + 4 + 8 = slave ID 13).
Please note: Each Procon A1M connected to the same RS-485 network must be set to a unique address.
3.2. Baud rate
The baud rate can be set to values from 1200 up to 115200 baud using DIP switches 6 – 8 as follows:
Baud rate Switch 6 Switch 7 Switch 8
1200 OFF OFF OFF
2400 ON OFF OFF
4800 OFF ON OFF
9600 ON ON OFF
19200 OFF OFF ON
38400 ON OFF ON
57600 OFF ON ON
115200 ON ON ON
3.3. Other communication settings
All other communication settings are fixed:
- 8 Data Bits
- No Parity
- 1 Stop Bit
3.4. RS-485 termination
RS-485 termination resistors can also be enabled on the A1M PCB using a single jumper. These settings are
summarised below:
Jumper Setting Description
Not connected No termination or pull-up resistors enabled
LK1 Pull-up resistor A enabled
LK2 RS-485 termination resistor enabled
LK3 Pull-down resistor B enabled