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APM303 Generator Controllers
This guide will show you how to connect the Polar Monitoring Gateway to the APM303 series generator controller. It will also take you through the setup and parameters required on the APM303 to ensure communications to the Polar Gateway.
Steps to follow:
- Connect power to the Gateway.
- Connect RS-485.
- Final checks.
- Power on the system.
- Configure the APM303 Serial Parameters
APM303 Connection Setup
1. Connect power to the Gateway.
Connect the Polar Gateway to a 12-24 V DC power supply. Connect the positive wire to the positive outlet and the negative wire to the negative outlet.
2. Connect RS-485
Connect the Modbus cable to allow communication with the Polar Gateway. Connect A+ to A+ and the B- to B-.
3. Final checks
Before you switch on the Gateway and the device make sure you have done everything correctly in the previous steps.
- Make sure the wiring is secure – no short circuits.
- Check if the power cables are not loosely wired to the Gateway.
- Check if the power cables are not loosely wired to the device.
- Re-check the RS-485 twisted pair cable is correctly wired.
4. Power on the system.
Now you are ready to go, you can now switch on the power to make some configuration changes for your Polar Portal.
5. Configure APM303 Serial Parameters
In order for the Gateway to correctly communicate with the APM303 controller, there will need to be some changes made to the communication parameters.
Note: It is critical to change the default settings to reflect the table below.
Serial Communication Setup
| Name | Description | Parameter | Default | Required |
| Address | Device ID/Unit ID/Node ID | M04 | 5 | 1 |
| Speed | Communication Speed | M01 | 1=9600 | 1=9600 |
| Parity | Error-checking process | M03 | 1=no | 1=no |
| Stop bit | End of data transmission | M02 | 1=1 stop bit | 1=1 stop bit |