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TOPIC: Delay in refresh time of SCADA value

Delay in refresh time of SCADA value 4 months 3 weeks ago #1772

Dear Team,
Delays in refresh time during communication between micrologix 1400 PLC and SCADA, this delay around 13-15 second
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Delay in refresh time of SCADA value 4 months 3 weeks ago #1775

  • fatkhrus
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Hello,

There are several possible reasons of that:
1. Check your communication between PLC and SCADA.
2. Try to increase poll interval of the server.
3. Try to increase update interval in project properties.
If all these settings up doesn't help you check your project.
Unfortunately our Micrologix driver (instead of Modbus and Siemens drivers) has only one mode - it reads only one register per request. During one poll interval it reads all tags (register) that has bound objects on the current screen and all tags that have checked history and event properties. If these number is too big and communication is not so fast it takes time.
Possible solution of this problem:
1. Create array for every file area that contains many registers like at the attached file:



2. Then in ST script (General, OnDataChange) split this array for the tags:
short array[20] = Tags.array;
Tags.value = array[0];
Tags.value = array[1];
during these request for reading this array will be only one and you'll get all needed tags.
3. And use readbit function for reading bits of the register:
Tags.somebitvalue = readbit(Tags.value, 1);
Best regards,
Ruslan
Last Edit: 4 months 3 weeks ago by fatkhrus.
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Delay in refresh time of SCADA value 4 months 1 week ago #1795

i have done all tags in array to read data... i want to know write bit in array... please provide solution to write bit in array tag...
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Delay in refresh time of SCADA value 4 months 1 week ago #1796

  • fatkhrus
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Hello,

You no need to write bit in the array. You have to open tag properties of the bit (in my example somebitvalue tag) and check "Output differs from Input" and choose your server (in your case Micrologix server) and choose register you want to change bit. Output tags do not requested every poll and you'll not have delays in this case.

Best regards,
Ruslan
Last Edit: 4 months 1 week ago by fatkhrus.
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