Timeouts

[tonyskalski]

Hi and thanks for a great module!

I read the other issue (now closed) related to timeouts, but I still have a problem. I am reading some values through a modbus gateway running on PowerLogic electric meter. If I query the meter itself, I get results. If I query a 'gateway' device (connected to the meter via RS-485) it times out.

I am using libmodbus 3.1.2 as recommended in the other timeout issue. I have timed the responses using tester.exe from Schneider Electric and they take ~2000 ms typically. I can also reproduce the issue with modpoll.exe - with the default timeout (1 sec) I usually receive a connect time-out error. If I increase the timeout to 2-3 seconds I get a value.

I have looked through the libmodbus code to see if there was an easy or obvious way to adjust, but I am not a programmer. Is there a way to set a timeout? Even a global option would help. Thanks!

[v-zhuravlev]

What error do you have in Zabbix (can check by clicking Red cross in 'Latest data' or in zabbix-*.log)? What does it say?

So it seems that the default libmodbus timeout is around 1 second or below it, right?

What Timeout do you have in Zabbix config? 3 seconds as by default?

[v-zhuravlev]

I guess that default timeout is 0.5s: https://github.com/stephane/libmodbus/blob/master/src/modbus-private.h#L38

And by uncommenting this line and recompiling the library you would probably get 10seconds timeout in libmodbus: https://github.com/v-zhuravlev/libzbxmodbus/blob/master/src/modbus.c#L290

I think a proper way would be to set modbus timeout with the value of Timeout that is in zabbix-*.conf file.

Anyway please answer the questions above :)

[tonyskalski]

2472:20161028:150355.123 item "ION 7550:modbus_read_registers[xxx.xxx.xxx.xxx, 5, 3, 3]" became not supported: Connection timed out

I get the same thing with the default, and also when 'Timeout=10'.

When I get back to the office Monday I will try adjusting https://github.com/stephane/libmodbus/blob/master/src/modbus-private.h#L38, re-make libmodbus and re-test. For my environment, having this set globally will not be a problem.

ajs

On Fri, Oct 28, 2016 at 6:35 PM, Vitaly Zhuravlev notifications@github.com wrote:

I guess that default timeout is 0.5s: https://github.com/stephane/libmodbus/blob/master/src/modbus-private.h#L38

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Tony Skalski Systems Administrator ajs@stolaf.edu 507-786-3227 St. Olaf College Information Technology 1510 St. Olaf Avenue Northfield, MN 55057-1097

[v-zhuravlev]

Adjust here and uncomment: https://github.com/v-zhuravlev/libzbxmodbus/blob/master/src/modbus.c#L290 Will have the same effect

[v-zhuravlev]

I added a commit with module version that uses Timeout from zabbix_agent file. Would be great if you could give it a test https://github.com/v-zhuravlev/libzbxmodbus/commit/09d619d1e40fa26b5df28e0d03e2a9c4c5a52755

[tonyskalski]

Tested successfully. Thanks!

This morning I tested by manually setting the timeout here https://github.com/v-zhuravlev/libzbxmodbus/blob/master/src/modbus.c#L290, but this is much better.

On Mon, Oct 31, 2016 at 2:35 PM, Vitaly Zhuravlev notifications@github.com wrote:

I added a commit with module version that uses Timeout from zabbix_agent file. Would be great if you could give it a test 09d619d https://github.com/v-zhuravlev/libzbxmodbus/commit/09d619d1e40fa26b5df28e0d03e2a9c4c5a52755

— You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub https://github.com/v-zhuravlev/libzbxmodbus/issues/11#issuecomment-257396868, or mute the thread https://github.com/notifications/unsubscribe-auth/AETX0BpNtH8Ja85tJkMVkL5d2Hrt0REFks5q5kL_gaJpZM4Kj5OH .

Tony Skalski Systems Administrator ajs@stolaf.edu 507-786-3227 St. Olaf College Information Technology 1510 St. Olaf Avenue Northfield, MN 55057-1097