PR55-34 message on sleep

I get the following packte from my PR55-34 after about an hour of inactivity, and at every hour thereafter:
[76, 73, 86, 69, 0] (or “LI8E\0” ASCII)
I thought it was corrupt data until I had a chance to play with it. It seems to be going into a sleep mode. The next Modbus request I send out wakes it to “FLY” mode, then “RUN” one minute later, after which it passes the Modbus packets as expected.
Is there a reference somewhere that describes this behavior?

Once an hour, the device sends a LIVE message. This message lets us know that the RS485 node is active. The FLY mode message, however, will only be sent after the device reboots. Is it possible that you’re sending a reboot command to the device?

The documentation is still in progress. The engineers are moving a bit faster than the documentation team. We have a new version of this device where users can program the register they want to read and set the read interval. The device will automatically read the set register and send the packet, essentially turning any RS485 device into an NCD sensor node.

This is a dead simple test flow I have set up locally. It just sends data with a modbus read registers packet when I click on the inject node. It appears to go to sleep if ignored for an hour.

What the firmware version?
Just to clarify you are saying its going in sleep if you don’t send any data?
What do you do bring it back?

It’s this one:

Yeah, if left powered on but not polled for >hr it seems to go to sleep, and report “LIVE” once per hour (sorry, my ascii was a little off before). It wakes to FLY mode when I send it a Modbus packet, but won’t respond for another minute, when it goes to “RUN” mode.

Guessing that’s kind of a corner case, since normally you’d be continuously polling the modbus device for data.

so once it goes in FLY mode it will stay in that mode for 60sec. during this 60 sec users can send any cfg commands to change any settings.
once its in run mode it will respond to all commands.

The only way it can go in FLY mode is

  1. power cycle
  2. master sends reboot command
    check all nodes in node red. there has to a node which is sending reboot command.

This device does not have sleep mode.