GE Fanuc RX3i Serial
Review the following information for setting up and configuring the GE Fanuc RX3i Serial driver. The driver communicates with the CPU's SNP port over RS-232 or RS-485.
Note: This driver is experimental. Some features might not work as expected.
Litmus Edge compatible series
Compatibility parameter | Compatible items |
|---|---|
Driver type | Serial (RS-232 or RS-485) |
Validated devices/series | Emerson / GE PACSystems RX3i CPUs with an SNP slave port: CPU310, CPU315, CPU320, CPE302, CPE305, CPE310 |
To set up and configure this device in Litmus Edge (LE), do the following:
- Step 1: Set up and configure the PLC device
- Step 2: Set up the PLC device in Litmus Edge DeviceHub
- Step 3: Configure the list of registers
Step 1: Set up and configure the PLC device
Record the serial communication parameters for the device. Otherwise, follow the steps below.
To configure your device:
- Note down the following information and refer to it when needed.
- Device: GE Fanuc RX3i
- Communication I/F: RS232, refer to the following figure.

- Launch Proficy Machine Edition v8.0 software to configure the serial port of the device.
A port left in its default RTU Slave mode switches to SNP when the driver connects with a blank SnpId. On a multi-drop line, note the SNP ID configured in the CPU port settings. You need it in Step 2.
Step 2: Set up the PLC device in Litmus Edge DeviceHub
Configure the following parameters when you Connect a DeviceConnect a Device with this driver. Update default values to the specific setup of your device.
Parameter | Value |
|---|---|
Type | GE Fanuc |
Driver | GE Fanuc RX3i Serial |
DeviceFile | The serial port path used to communicate with the device, for example /dev/ttyS1 or /dev/ttyUSB0. Default value /dev/ttyS0 |
BaudRate | Must match the baud rate configured on the device. Select a value from 1200 to 921600. Default value 19200 |
DataBits | 5, 6, 7, or 8. Must match the device. Default value 8 |
Parity | None, Odd, or Even. Must match the device. Default value Odd |
StopBits | 1, 1.5, or 2. Must match the device. Default value 1 |
The following parameters are under Advanced Parameters.
Parameter | Value |
|---|---|
MaxRequestSize | The maximum register payload in one request, in bytes. Enter a value from 6 to 1000. Lower it if the CPU refuses large blocks. Default value 200 |
SnpId | The SNP ID of the PLC, up to seven characters (A to Z, 0 to 9, and _). Leave it blank for a point-to-point connection. Set it only on a multi-drop line, to the ID configured in the CPU port settings. |
ReadTimeout | How long the driver waits for a response, in milliseconds. Enter a value from 10 to 10000. Default value 2000 |
RetryCount | The number of times a failed request is retried. Enter a value from 0 to 5. Default value 0 |
PauseBetweenRetries | The pause between retries, in milliseconds. Enter a value from 0 to 2000. Default value 0 |
For the Meta Data, Status Register, and Optional Settings options, see Connect a DeviceConnect a Device. By default, the status register is R, value type uint16, address 1.
Step 3: Configure the list of registers
When you Add a TagAdd a Tag to the connected device, see the following register table and tag parameters. This driver does not support browsing tags.
See the following additional resources if necessary:
- Organize Device and Tag Data by Using MetadataOrganize Device and Tag Data by Using Metadata
- Tag Formula VariablesTag Formula Variables
Register table
Addresses start at 1 and match the PLC reference numbers. For example, %R1 is R address 1.
The maximum addresses are the RX3i family limits. A CPU configured with a smaller memory map rejects addresses past its own limit.
Name | Description | Value Types | Access Type | Address Format | Min Address | Max Address |
|---|---|---|---|---|---|---|
I | Discrete inputs (%I) | bit | R/O | DDDDD | 1 | 32768 |
Q | Discrete outputs (%Q) | bit | R/W | DDDDD | 1 | 32768 |
M | Internal coils (%M) | bit | R/W | DDDDD | 1 | 32768 |
G | Genius global data (%G) | bit | R/W | DDDDD | 1 | 32768 |
T | Temporary coils (%T) | bit | R/W | DDDDD | 1 | 32768 |
SA | System status bits (%SA) | bit | R/W | DDD | 1 | 128 |
SB | System status bits (%SB) | bit | R/W | DDD | 1 | 128 |
SC | System status bits (%SC) | bit | R/W | DDD | 1 | 128 |
S | System status bits (%S) | bit | R/O | DDD | 1 | 128 |
R | Registers (%R) | uint16 | R/W | DDDDD | 1 | 32768 |
AI | Analog inputs (%AI) | uint16 | R/O | DDDDD | 1 | 32768 |
AQ | Analog outputs (%AQ) | uint16 | R/W | DDDDD | 1 | 32768 |
Tag parameters
- Name: Select a register name from the drop-down list. The available options depend on the names in the register table.
- Value Type: Select a data type from the drop-down list. The available options depend on the register name selected.
- Address: Enter the register address in decimal format, within the min and max range in the register table. Omit leading zeros.
- PollingInterval: Enter how often the tag polls for data, in seconds. Enter 0 to disable polling. Default value 1
- Tag Name: Enter a name for the tag.
- Description (Optional): Enter a description for the tag.
- Tag Formula: Enter a formula for the tag to process the generated data. You can use two variables: value (current tag value) and timestamp (current tag UNIX time in milliseconds). The following math functions are available:
- sin
- cos
- sqrt
- tan
- power: power(x) performs the operation 10^x.
- log: log(x) is the natural logarithm (the logarithm is in base e).
- exp: exp(x) performs the operation e^x.
- Only Publish on Change of Value: Select the checkbox to publish NATS messages only when the value parameter changes. Change of Value only applies to boolean, numeric (such as int or float), and simple string data types. It does not apply to complex types, such as JSON or array. Poll-once topics are not affected by Change of Value settings, and still receive a single message.
- Meta Data: Define key-value pairs to add to the device output payload.
Note: If you use special characters in metadata key names, the special characters are replaced with underscore characters in the payload. This can cause two key names to be combined into one. For example, configuring the key names a**b and a&&b creates only one key name (a__b).