Allen Bradley timeout

Ignition
1

I have a DH+ network with AllenBradley , I am using an AllenBradley gateway to read the DH+ plcs throught ethernet, but I have many timeout errors in IGNITION from those PLCs, any idea?
thanks

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2

How many tags are involved? Have you looked at the device's diagnostics page?

{ Timeouts often mean "badly overloaded comms", which is really easy to do with old, very slow protocols, like DH+.)

3

Around 500 tags
is there a way to fix this "Overloaded comms"?

4

See this comment about throttled SLC 5/05 traffic, the 5/04 has similar throttles:

If those aren't your problem, then you should check if you are running your DH+ at 230k. If not, you can get a 4x improvement by converting (all devices on the channel must be capable of this, and be configured together).

Other than that, no. You'll just have to go slower. (Tag group rate.) You can only fit so much [expletive] in a one-pound bag. (The normal euphemism is ten pounds in a five-pound bag, but DH+ is a much smaller "bag".)

5

thanks

6

I just noticed that your OP indicates plural "PLCs". If there are multiple PLCs on a single DH+ channel, a couple other factors to consider:

  • The bandwidth is shared. So the number of tags that matter is the number across all of the PLCs on a channel.

  • Throttling in any of the PLCs will cause a response to be delayed, delaying all of the PLCs.

  • Any PLC that is powered down will not respond for its turn, timing out and affecting all other PLCs on the channel. It is imperative that the Ignition device be disabled when its PLC is unresponsive.

7

My new quote for the week.

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