Modbus is a standard communication protocol that is supported by many devices. All ETC plunger lift controllers use COM1 as a Modbus Slave port that will receive commands from a Master device located on a centralized server.
COM1 is disabled by default to save power.
Enable Modbus
To enable Modbus on the controller or simulator, follow these steps:
- Press the install key.
- Log in if security has been enabled
- Navigate up or down until you find the Modbus menu item and press select.
- Press select to edit the field.
- Scroll down to enable and press select.
- Proceed to modify the other required settings.
Modbus Settings
Other settings are provided so that the communications can be configured to match the settings of the device that is connected to the controller.
Station Address
This is the slave address that the master uses to identify a particular slave device.
- Default: 1
- Valid Values: 1 to 247
Protocol
This defines the data transport as either binary data (RTU) or characters (ASCII).
- Default: RTU
- Valid Values: RTU, ASCII
Baud Rate
Communication speed in bits per second (bps).
- Default: 9600
- Valid Values: 1200, 2400, 4800, 9600, 19200
Data Bits
Number of bits used to send the data per
- Default: 8
- Valid Values: 7 or 8
Parity
Error detection method
- Default: None
- Valid Values: None, Even, Odd
Stop Bits
Number of bits to indicate the end of character
- Default: 1
- Valid Values: 1 or 2
Time Format
This allows the user to specify how time based values are represented in the Mobus registers. This can either be in seconds since Jan 1, 2000 or Hours:Minutes:Seconds.
- Default: Seconds
- Valid Values: Seconds, H:M:S