While using sync.client, _recv() too early after _send()

[Edke]

Hello.

Spent two days figuring this, but this helped an issue. I'm querying a device, that is a bit slow in response via Modbus. Using sync.client and TCP Server ICS-10X from Planet gave me a headache. Was not able to get result of ReadHoldingRegistersRequest():

DEBUG:pymodbus.transaction:Running transaction 1
DEBUG:pymodbus.transaction:getting transaction 1
DEBUG:pymodbus.transaction:Running transaction 2
DEBUG:pymodbus.transaction:getting transaction 2

After modifying of ModbusTransactionManager's execute() and putting delay between _send() and _recv() everything works great:

DEBUG:pymodbus.transaction:Running transaction 1
DEBUG:pymodbus.factory:Factory Response[3]
DEBUG:pymodbus.transaction:adding transaction 0
DEBUG:pymodbus.transaction:getting transaction 1
Slave: 3, register 23: 0x4041
DEBUG:pymodbus.transaction:Running transaction 2
DEBUG:pymodbus.factory:Factory Response[3]
DEBUG:pymodbus.transaction:adding transaction 0
DEBUG:pymodbus.transaction:getting transaction 2
Slave: 3, register 24: 0x5268

Don't know if this can be achieved with some more elegant approach but this works for me so far. Would be great if such a delay would be configurable.

[bashwork]

Edke, let me know if this solution will work with you. What you can do is increase the retry count and then specify that empty responses should count as retries::

client = ModbusTcpClient('localhost', retry_on_empty = True, retries = 5)

[mesias]

I've created this option "retry_on_empty" last week. And additionally
creted "retry_on_wrong" when receives on Serial RTU from wrong unit or
function.

On Mon, Jul 15, 2013 at 1:44 AM, Galen Collins notifications@github.comwrote:

Edke, let me know if this solution will work with you. What you can do is
increase the retry count and then specify that empty responses should count
as retries::

client = ModbusTcpClient('localhost', retry_on_empty = True, retries = 5)

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Reply to this email directly or view it on GitHubhttps://github.com//issues/21#issuecomment-20951634
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Alejandro Mesias André Nebra Perez
Java/Python/Js/Something else Developer
Twitter: @meszias
Linux User #442506

Campinas - SP - Brasil - South America

[Edke]

@bashwork @mesias No new version, so only have to test it with pip install from git, right ?

[bashwork]

That is correct.
On Jul 15, 2013 1:13 PM, "Eduard Kracmar" notifications@github.com wrote:

@bashwork https://github.com/bashwork @mesiashttps://github.com/mesiasNo new version, so only have to test it with pip install from git, right ?

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Reply to this email directly or view it on GitHubhttps://github.com//issues/21#issuecomment-21000201
.

[Edke]

@bashwork will test it tomorrow, have 150 devices on Modbus link via TCP/IP converter and really have issues with communication. Will report back if related changes will address the issue for me.

[mesias]

@Edke The version i wrote (https://github.com/mesias/pymodbus) reads single bytes on transaction, instead of 1024bytes. It's a bit faster, but never tested on any different connection than Serial RTU.