--- title: LS Serial slug: litmusedge/quickstart-guide/industrial-systems-connection-guide/ls-industrial-system/ls-serial description: Review the following information for setting up and configuring the LS Serial driver. docTags: createdAt: 2026-10-12T01:57:09.379Z --- Review the following information for setting up and configuring the LS Serial driver. The driver connects to LS Electric (LSIS) PLCs over a serial line. It supports three link protocols, which you select with the **LinkProtocol** device setting: - **XGT dedicated (Cnet)**: XGT family CPUs through a Cnet module (XGL-CH2A or XBL-C21A) or the XBM built-in Cnet channel. RS-232C point-to-point, or RS-485 multidrop with up to 32 nodes. - **XGT CPU-Direct**: The loader port of an XGB, XBM, XBC, or XGK CPU. - **Master-K CPU-Direct**: The loader port of a Master-K CPU. This driver replaces the LS XBM Cnet Serial, LS XBM Serial, and LS Master-K CPU Direct Serial drivers. :::hint{type="info"} **Note:** This driver is experimental. Some features might not work as expected. ::: # Litmus Edge compatible series | Compatibility parameter | Compatible items | | ---------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | **Driver type** | Serial (RS-232C or RS-485) | | **Validated devices/series** | LS Electric XGT Series:
XGB, XBM, XBC, XGK
Cnet modules XGL-CH2A and XBL-C21A
LS Electric Master-K Series:
K7M
[LS Electric K80S](https://sol.ls-electric.com/product/document/2445)
[LS Electric K120S](https://www.ls-electric.com/products/view/Smart_Automation_Solution/PLC/MASTER-K_Series/K120S)
[LS Electric K200S](https://sol.ls-electric.com/product/document/2436)
[LS Electric K300S](https://sol.ls-electric.com/product/document/2436)
[LS Electric K1000S](https://sol.ls-electric.com/product/document/2436) | 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, and note which port the cable is connected to. The **LinkProtocol** you select in Step 2 must match that port. The three protocols are not compatible with each other. A mismatch causes no reply or a rejected frame, not a clear error. The driver does not detect the baud rate automatically. The serial settings in Step 2 must match the port exactly. The device defaults are 115200 baud, 8 data bits, no parity, and 1 stop bit for both XGT protocols, and 38400 baud, 8 data bits, no parity, and 1 stop bit for Master-K. ## XGT dedicated (Cnet) In XG5000, set the operation mode of the Cnet channel to **XGT server**. The CPU keeps this setting after a power cycle. If the channel is set to **Modbus RTU server**, **Modbus ASCII server**, or **Use P2P**, the device does not reply to the driver. Also note the station number of the channel. You enter it as **StationId** in Step 2. ## XGT CPU-Direct The loader port needs no extra setup. **To check the connection to your device:** 1. Note down the following information and refer to it when needed. - **Device**: LS XBM-DR165 - **Communication I/F**: RS232. Refer to the following figure. ::Image[]{src="https://api.archbee.com/api/optimize/SSUUxKZUk9bFTEPNn_6Zo/Z12vA1LDvmBuvrKLc5lcf_ls-xbm-serial-reference.png" size="80" width="398" height="861" position="flex-start" caption="LS XBM Serial reference" darkWidth="398" darkHeight="861" showCaption="true"} 2. Launch XG5000 v.3.71 software and click **Online** > **Online Settings**. 3. Set up the COM port, and then click **Auto Detect**. ## Master-K CPU-Direct The loader port needs no extra setup. **To check the connection to your device:** 1. Note down the following information and refer to it when needed. - **Device**: LS Industrial Systems - **Communication I/F**: RS232. Refer to the following figure. ::Image[]{src="https://api.archbee.com/api/optimize/SSUUxKZUk9bFTEPNn_6Zo/D2BMrU-96nvCTBps28UAh_ls-master-k-cpu-direct-serial-reference.png" size="80" width="650" height="511" position="flex-start" caption="LS Master-K CPU Direct Serial reference" darkWidth="650" darkHeight="511" showCaption="true"} 2. Launch KGL\_WE v3.66 software and click **Project** > **Option** > **Connection Option**. 3. Set up the COM port. 4. Click **Connect**. # Step 2: Set up the PLC device in Litmus Edge DeviceHub Configure the following parameters when you [Connect a Device](docId\:pF5pwEP7Ata1NC7c0yQu_) with this driver. Update default values to the specific setup of your device. | Parameter | Value | | ---------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | **Type** | LS Industrial System | | **Driver** | LS 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 `115200`. For Master-K, the device default is `38400`. | | **DataBits** | 5, 6, 7, or 8. Must match the device. Default value `8` | | **Parity** | None, Odd, or Even. Must match the device. Default value `None` | | **StopBits** | 1, 1.5, or 2. Must match the device. Default value `1` | | **LinkProtocol** | The link protocol of the port the cable is connected to. Select **XGT dedicated (Cnet module / built-in Cnet channel)**, **XGT CPU-Direct (loader RS-232 port)**, or **Master-K CPU-Direct (loader RS-232 port)**. Default value **XGT dedicated (Cnet module / built-in Cnet channel)** | | **StationId** | For XGT dedicated (Cnet) only. The Cnet station number of the channel. Enter a value from `0` to `255`. Default value `1` | The following parameters are under **Advanced Parameters**. | Parameter | Value | | ----------------------- | ------------------------------------------------------------------------------------------------------------------- | | **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 Device](docId\:pF5pwEP7Ata1NC7c0yQu_). By default, the status register is `MW`, value type `uint16`, address `0`. # Step 3: Configure the list of registers When you [Add a Tag](docId:89nruY50cZN0cPLIOmVdl) 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 Metadata](docId\:gSM6iJPWjd0cCxWq2Qre2) - [Tag Formula Variables](docId\:Xj0OqYONxM2BEhMwqkDWC) ## Register table All addresses start at `0`. Each tag reads one value. - **Word registers** address a word directly and use `uint16`. - `_bit`** registers** address a bit inside a word. Enter the word number followed by a two-digit bit number, from `00` to `15`. For example, address `10005` is bit 5 of `MW100`. - `SX` addresses a step. Enter the group number followed by a two-digit step number, from `00` to `99`. - `TX`** and **`CX` address a timer or counter contact by its number. The maximum addresses are the widest limits across all three CPU families. Some registers are not available on every link protocol. If you use one, the driver returns a configuration error and sends no request. - Not available on Master-K CPU-Direct: `SW`, `NW`, `ZW`, `ZRW`, `UW`, `UW_bit`, `RW`, `RW_bit`, `TSW`, and `CSW`. - Not available on XGT dedicated (Cnet): `ZRW`, `TSW`, and `CSW`. | **Name** | **Value Types** | **Access Type** | **Address Format** | **Min Address** | **Max Address** | **Description** | | -------- | --------------- | --------------- | ------------------ | --------------- | --------------- | --------------------------- | | PW | uint16 | R/W | DDDD | 0 | 2047 | I/O Relay | | PW\_bit | bit | R/W | DDDDdd | 0 | 204715 | I/O Relay | | MW | uint16 | R/W | DDDD | 0 | 2047 | Auxiliary Relay | | MW\_bit | bit | R/W | DDDDdd | 0 | 204715 | Auxiliary Relay | | LW | uint16 | R/W | DDDDD | 0 | 11263 | Link Relay | | LW\_bit | bit | R/W | DDDDDdd | 0 | 1126315 | Link Relay | | KW | uint16 | R/W | DDDD | 0 | 2559 | Keep Relay | | KW\_bit | bit | R/W | DDDDdd | 0 | 255915 | Keep Relay | | FW | uint16 | R/W | DDDD | 0 | 2047 | System Flag Relay | | FW\_bit | bit | R/W | DDDDdd | 0 | 204715 | System Flag Relay | | DW | uint16 | R/W | DDDDD | 0 | 32767 | Data Register | | DW\_bit | bit | R/W | DDDDDdd | 0 | 3276715 | Data Register | | UW | uint16 | R/W | DDDD | 0 | 6331 | Analog Refresh Register | | UW\_bit | bit | R/W | DDDDdd | 0 | 633115 | Analog Refresh Register | | RW | uint16 | R/W | DDDDD | 0 | 32767 | File Register | | RW\_bit | bit | R/W | DDDDDdd | 0 | 3276715 | File Register | | SX | bit | R/W | DDDDD | 0 | 12799 | Step Control Flag | | TX | bit | R/W | DDDD | 0 | 2047 | Timer Contact | | CX | bit | R/W | DDDD | 0 | 2047 | Counter Contact | | SW | uint16 | R/W | DDD | 0 | 127 | Step Control Group | | NW | uint16 | R/W | DDDDD | 0 | 21503 | Communication Data Register | | ZW | uint16 | R/W | DDD | 0 | 127 | Index Register | | TW | uint16 | R/W | DDDD | 0 | 2047 | Timer Current Value | | CW | uint16 | R/W | DDDD | 0 | 2047 | Counter Current Value | | ZRW | uint16 | R/W | DDDDD | 0 | 32767 | Extended File Register | | TSW | uint16 | R/W | DDDD | 0 | 2047 | Timer Setting Value | | CSW | uint16 | R/W | DDDD | 0 | 2047 | Counter Setting Value | ### Writing to FW, FW\_bit, and NW You can write to `FW`, `FW_bit`, and `NW` on every link protocol, but the result depends on the device: - On both CPU-Direct protocols, an `FW` write is only partly applied. The value is combined with the current word by a bitwise OR. - An `FW_bit` write is accepted but has no effect. - An `NW` write is rejected by the device, but it can still change data in the area. - On XGT dedicated (Cnet), the CPU rejects `FW` and `NW` writes with NAK `1132`. Read these registers freely, and write to them only when you intend to. ### Master-K addresses :::hint{type="warning"} **Warning:** Master-K CPU-Direct does not check address ranges. An address past the end of an area reads or writes the next area in memory, with no error. A read returns the next area's data, and a write overwrites it. ::: The following table shows the documented extent of each area and where it runs into the next area. Confirm the extent for your CPU model before you use an address near a limit. | **Area** | **Documented extent** | **Runs into** | **At word** | | --------------- | --------------------- | ----------------- | ----------- | | `PW` / `PW_bit` | 63 | `MW` | 128 | | `MW` / `MW_bit` | 191 | `LW` | 256 | | `LW` / `LW_bit` | 63 | `KW` | 128 | | `KW` / `KW_bit` | 31 | `TX` | 128 | | `FW` / `FW_bit` | 31 | `SX` step control | 128 | ## 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. For `_bit` registers, add the two-digit bit number at the end. - **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. :::hint{type="info"} **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). :::