# Mitsubishi SLMP

Mitsubishi MELSEC PLC devices right in the chat

ПЛК Mitsubishi MELSEC Q, L, iQ-R, iQ-L и iQ-F по устройствам через назначенный шлюз, только чтение

## How the agent works with Mitsubishi SLMP

Data is read by the gateway: a program installed as a service on a computer or server on the site network that reaches the PLC over SLMP, frame 3E binary over TCP. The connection takes the PLC address with the port of its SLMP connection setting, the PLC series and a tag map: one line per tag with a path, a GX Works device and a type, such as D100 real or M10 bool. The gateway sends data out over outbound connections only.

Frame 3E has no serial number to tie an answer to its request, so the gateway keeps one request at a time and checks that the connection is silent before the request and after the answer; a surplus byte drops the link instead of reaching another tag. Tags of one device standing at most 64 words apart are read in one request of up to 960 words. Bit devices are read as words of 16 points, and iQ-F double words and LZ go by random read of up to 96 points.

The driver only reads: of the SLMP commands it sends batch read 0401 and random read 0403. It has no device change, no remote CPU control and no password commands. An end code about a device marks the tags of that request bad while the others keep reading; a remote password on the port gives access denied.

The PLC series is required: it decides the request form and which devices exist, and on iQ-F also the octal numbers of X and Y. MELSEC keeps wide values low word first and a string's first character in a word's low byte. FX3U and the A series speak another frame, 1E, and are not read by this driver. If the link to the cloud drops, data piles up on the gateway's disk and arrives once it is back.

## Integration scenarios

### What is on the line now
The agent finds tags by path, such as line1/press, and shows current values of D registers, M relays and X inputs with their timestamp and whether they are fresh.

### Shift summary
The agent takes the temperature, pressure or speed history for a shift and shows the minimum, maximum, average and last value per hour.

### Cycle count
The agent takes a week of raw samples of a cycle bit, such as M100, and counts cycles per day and the time between them.

### A task on a threshold
The agent sets up a task that fires when a tag goes past a threshold and stays there for a set time, not on every sample past it.

### Tags the PLC refuses
The agent names tags the CPU refused with the end code, such as C056 (a number past the end of the device), and suggests what to fix in the tag map.

### Gaps in the data
The agent shows history intervals without samples and says whether the site gateway is online right now.

## How to connect

**Before you connect**

- A MELSEC Q, L, iQ-R, iQ-L or iQ-F PLC with an Ethernet port
- An SLMP connection over TCP with the Binary data code in GX Works
- A free SLMP port with no remote password
- Network access to that port from the gateway computer
- A computer on the site network for the gateway service
- Tag devices from the GX Works project

### Add an SLMP connection in GX Works
In the PLC's Ethernet port settings add an SLMP connection over TCP and give it a port. SLMP has no standard port: enter this number in the connection address.

### Choose the Binary data code
The connection's communication data code has to be Binary. The gateway speaks frame 3E in binary, and a port set to ASCII may not answer at all.

### Keep the port for one client
An SLMP port takes one client. If an operator panel or another gateway holds it, the gateway cannot connect; a remote password on the port gives access denied.

### Check the PLC series
The series decides addressing: on iQ-F inputs X and outputs Y are octal, and a wrong series reads other inputs with no error. FX3U and the A series are not read in 3E.

## FAQ

### How do I connect Mitsubishi SLMP?
Add an SLMP connection over TCP with the Binary data code in GX Works and note its port. Add a gateway on the Gateways tab and install it as a service on a computer on the site network. In the connection enter the address with that port, such as tcp://10.0.12.5:1025, the PLC series and a tag map. Assign the connection to the gateway and it starts polling.

### What does the agent see in Mitsubishi SLMP?
The tags of the map: D and W registers, M relays, X inputs and Y outputs, ZR file registers, timer and counter current values and the other devices of the series. For each tag the agent reads the current value with its timestamp, the history in intervals and raw samples.

### Does the agent change values in the PLC?
No. The driver sends only batch and random reads. It has no device writes, no remote CPU run or stop and no password commands.

### The connection stays silent. What should I check?
First the connection's data code: a port set to ASCII may not answer at all. Then whether the port is taken: an SLMP connection takes one client, and an operator panel may hold it. Code C059 means the PLC does not take the command, most often because the series is wrong.