ET48A08 FAQ

Hello. I have a problem with ET48A08 8 channel relay. When sending commands according to rs485 protocol, it freezes during the first minutes of operation. And precisely when sending commands

 

Answer : 

1 Is the command sent through the RS485 interface or through Ethernet?
2 If it is abnormal in the first few minutes, can it work normally afterwards?

 

Question : 

We work in rs485 mode. The commands are correct. During some time everything work normally, but after random command the module freezes. Sometimes it begin to work again  in several seconds, but sometimes it freezes and only power outage can help

 

Answer :

Are the random commands incorrect instructions? Or are the commands correct, just sent at random times?

As I understand, each command time interval should be more than 0.25 sec?

Question :

The commands are correct

 

Answer : 

The sending interval may be too short. It is recommended that the interval between each command should be more than 250MS.

 

Question :

As I understand, each command time interval should be more than 0.25 sec?

Answer :

YES 

 

Question :

Otherwise for some reason  rs485 module freezes

Please explain, which command I must send to get the status of all 8 relay? For status checking of the first relay I send 01 03 00 00 00 01 84 0A, and for all 8 relay?

 

Answer : 

You can control 8 relays through the 0X0070 register, which is a BIT representing a relay. 0=OFF, 1=ON.
For example:
Channel 1 ON: 01 06 00 70 00 01 49 D1
Channel 1 OFF: 01 06 00 70 00 00 88 11
Channel 2 ON: 01 06 00 70 00 02 09 D0
Channel 2 OFF: 01 06 00 70 00 00 88 11

 

 

Question :

 

It was determined that the cause of the freezes was interference from the electromagnetic starter. But please explain - Is there a single command to query the current status of all 8 relays, or is it necessary to poll the status of each individual command?

 

Answer : 

Use the 03 command to read the 0X0070 register to read the status of 8 relays. Command: 01 03 00 70 00 01 85 D1