LS Serial

12 min

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.

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 LS Electric K120S LS Electric K200S LS Electric K300S LS Electric K1000S

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:

Note down the following information and refer to it when needed.

Device: LS XBM-DR165

Communication I/F: RS232. Refer to the following figure.

LS XBM Serial reference

Launch XG5000 v.3.71 software and click Online > Online Settings.

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:

Note down the following information and refer to it when needed.

Device: LS Industrial Systems

Communication I/F: RS232. Refer to the following figure.

LS Master-K CPU Direct Serial reference

Launch KGL_WE v3.66 software and click Project > Option > Connection Option.

Set up the COM port.

Click Connect.

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	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 DeviceConnect a Device. By default, the status register is MW, value type uint16, address 0.

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

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	Max Address	Description
PW	uint16	R/W	DDDD	2047	I/O Relay
PW_bit	bit	R/W	DDDDdd	204715	I/O Relay
MW	uint16	R/W	DDDD	2047	Auxiliary Relay
MW_bit	bit	R/W	DDDDdd	204715	Auxiliary Relay
LW	uint16	R/W	DDDDD	11263	Link Relay
LW_bit	bit	R/W	DDDDDdd	1126315	Link Relay
KW	uint16	R/W	DDDD	2559	Keep Relay
KW_bit	bit	R/W	DDDDdd	255915	Keep Relay
FW	uint16	R/W	DDDD	2047	System Flag Relay
FW_bit	bit	R/W	DDDDdd	204715	System Flag Relay
DW	uint16	R/W	DDDDD	32767	Data Register
DW_bit	bit	R/W	DDDDDdd	3276715	Data Register
UW	uint16	R/W	DDDD	6331	Analog Refresh Register
UW_bit	bit	R/W	DDDDdd	633115	Analog Refresh Register
RW	uint16	R/W	DDDDD	32767	File Register
RW_bit	bit	R/W	DDDDDdd	3276715	File Register
SX	bit	R/W	DDDDD	12799	Step Control Flag
TX	bit	R/W	DDDD	2047	Timer Contact
CX	bit	R/W	DDDD	2047	Counter Contact
SW	uint16	R/W	DDD	127	Step Control Group
NW	uint16	R/W	DDDDD	21503	Communication Data Register
ZW	uint16	R/W	DDD	127	Index Register
TW	uint16	R/W	DDDD	2047	Timer Current Value
CW	uint16	R/W	DDDD	2047	Counter Current Value
ZRW	uint16	R/W	DDDDD	32767	Extended File Register
TSW	uint16	R/W	DDDD	2047	Timer Setting Value
CSW	uint16	R/W	DDDD	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

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:

sqrt

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).