Browse pending and download mode

Hi everyone!
I have some devices (PLCs connected to scada through a gateway) that often go in “browse pending” or “Download Mode”, so tags from that devices aren’t updated and It happens to lose data.
Every time I saw devices in this status, I tried to disable and then to enable device and it works.

Which could be the reasons of this beaviour and, is it possible to set an alert that send me an e mail in case of Browse pending (so the status is still connected)or download mode?

Thank you for your help

Where do you see the “Browse pending” status? Is that on an OPC server in the Ignition gateway status page (see screenshot)?

image

Or are you using a different PLC driver, and what type of PLC?

If it’s OPC, you can use the system.opc.getServerState to check the state of the OPC device, and system.opc.setServerEnabled to False and True to reset the connection.

I’ve had to do this when we had a quite unreliable network, and in 1% of the cases, the PLC wouldn’t come back online after losing connection. It would get stuck in “Connecting” status. But I’ve never seen a PLC hang in the statuses you mention.

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I saw this status in the devices list in configuration area (under opc-ua server section).

Then you probably need to use the system.device.* functions.

AFAIK, those functions are used for PLCs with custom drivers. Though we don’t use those functions, as we always connect via OPC.

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Thank you for your help…
our PLCs are Allen Bradley and yes I’m talking about device connetivity.
I saw that this system.device function allows me to see (for example) my device list but I don’t know
if I can see device status to put an alert.
thank you!

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The device state is part of the dataset that is returned. Example from my server

row | Name                         Enabled State                       Driver      
-----------------------------------------------------------------------------------
 0  | 3501_EZPLC                   False   Disabled                    ModbusTcp   
 1  | 3502_Wintriss                False   Disabled                    ModbusTcp   
 2  | 3501_Wintriss                False   Disabled                    ModbusTcp   
 3  | 3502_EZPLC                   False   Disabled                    ModbusTcp   
 4  | Engel                        True    Disconnected                ModbusTcp   
 5  | PM_3220_3701                 True    Connected                   ModbusTcp   
 6  | Simulator1                   True    Connected                   Simulator   
 7  | SLC_SIM                      True    Connected                   SLCSimulator
 8  | 3220_Husky                   True    Disconnected                ModbusTcp   
 9  | DT1_Andon                    True    Connected                   LogixDriver 
 10 | Jordan Micro850              True    Connecting                  ModbusTcp   
 11 | DS1_Andon                    True    Connected                   LogixDriver 
 12 | DS2_Andon                    True    Connected                   LogixDriver 
 13 | DS3_Andon                    True    Connected                   LogixDriver 
 14 | DS4_Andon                    True    Connected                   LogixDriver 
 15 | DT2_Andon                    True    Connected                   LogixDriver 
 16 | DT3_Andon                    True    Connected                   LogixDriver 
 17 | DT4_Andon                    True    Connected                   LogixDriver 
 18 | PowerMonitor East Mains      True    Connected: Protocol: Direct SLC         
 19 | PowerMonitor Buss A          True    Connected: Protocol: Direct SLC         
 20 | PowerMonitor Compressor Room True    Connected: Protocol: Direct SLC         
 21 | DT_Riveter1                  True    Connected                   LogixDriver 
 22 | DT_Riveter2                  True    Connected                   LogixDriver 
 23 | Jordan CLogix                True    Connecting                  LogixDriver 
 24 | Cable_Andon                  True    Connected                   LogixDriver 

That being said, I usually only keep browsing on long enough to do the initial development. After that, I will turn it off and use system.device.refreshBrowse() to update only when necessary.

2 Likes

@rea_21 what ended up being your issue here? Im facing a similar problem now.

1 Like

I am having this problem also.

Ignition 7.9.17

Even with “Disable Automatic Browse” checked the CompactLogix devices status will switch back and forth between Browse Pending and Download without going back to Connected.

If I just edit the device and save (no changes) it will go back to connected and stay that way for several hours. Then the problem comes back.

1 Like

Im having the same issue did you every find a result?

Hello, i’m having the same issue


so, i enter to edit the device, save without changes, goto run state, and a few minutes later goes back to pending.
Any advice?

This is happening my gateway now.

What is the solution?
It is happening constantly, randomly seemingly moving through each EIP protocol connected machine.
Sometimes 2 at a time, sometimes just 1 at a time.
I will do a support ticket probably.
Thought maybe someone found a solution before.

8.1.19 version here

I had this once, and it turned out to be a bad patch cable.

Impacted multiple machines?

I would suspect a flaky network switch. This is going to be a network issue.

In my case, only up to 2 plcs disconnect at a time.
Note more than 2.
So I thought maybe something is begin overrun.

For my system, it looks like pushing 14 things through a hole, and a random 2 fallout regularly.

How do I know if this is a physical connection issue?
Or how do I know if this is an overrun situation?
I have timestamps for the resets.
They seem kind of far apart though, so not a physical connection issue?
Maybe many happened at 10:42, so it is physical?

Below is a a list of recent resets on the log, and maybe the timing can help with troubleshooting.

I numbered the machines, but one is a group of machines on the other side of the facility.
The "group" one is like one plc for many machines.

Pushed on ethernet plugs.
Disconnected one machine that had a script with OPC reads.
Reconnected it.

Issue is gone.
Did not find the cause yet.
Hasn't come back in a couple of hours.


The resets came back, another hour later.

Do they all run into a common switch? Is the switch powered through an APC? I've seen the battery start to fail in those, and when that happens, they will randomly cycle.

They go to a switch.
Across an ethernet cord.
Into the server network port.
Into the VM, and finally into the Gateway.

Then also, there are a ton of tag reads/writes and opc reads that I am concerned about.

It's not your fault. With confidence, tell the network guys that the problem is on there end, and I'm sure they will find the problem and fix it.

If it is legitimately too many devices trying to talk over each other (usually 500+), then they will simply need to split the network with a router or a switch with routing capabilities. However, if the network has been running for sometime without this problem, and no devices have been added recently, then it's probably a simple hardware or cabling issue.

One of my ports is limited to 100mb.

That is too tight in general for 60 plcs to talk to the gateway?
I don't have a good concept of the rule of thumb.

Or is a connection limited to 100mb like that a good means to insure that the gateway data is limited before the plcs are overrun?