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#1 16-12-2011 09:31:55

lars.martin
Member
Registered: 16-12-2011
Posts: 1

Receiving 65535 from several P8511 via modbus

Hi,

we have some problems with modbus connections from the P8511 temperature sensors. We poll the sensors with an interval of 1 second and sometimes we receive over a longer timeperiode (10-20s) the value of 65535 from the sensors. Is this value an error code and what can we do to avoid this situation.

Best Regards

Lars Martin

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#2 16-12-2011 09:55:15

HonzaD
Administrator
Registered: 11-08-2008
Posts: 294

Re: Receiving 65535 from several P8511 via modbus

Hello Lars,

I haven't heard about this problem before. But I think reading interval is too fast. Device measure temperature with interval 2 sec. Fastest reading not make sense from this reasons:

- reading interval is 2 sec
- response time of useed probe is not faster than ~3 sec


A few hints:

- decrease reading interval to 5 sec (or better 10 sec)
- close TCP connection after every communication (open socket, send command, wait for answer, read answer, close socket)




John

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