Service Request 7

rodrigfluis · Sep 13, 2019

Hello, All,

I am very new to the PLC programming world. The company I work for uses GE Versamax Micro Plus Controllers and Proficy Machine Edition. My current project requires that I develop a program that will turn a heater on at 4:00 AM and turn it off at 2:00 PM.

It seems that Service Request 7 may be what I need; however, I am struggling with understanding how time and date information are accessed and used with the Service Request 7 Function. Would anyone be willing to shed some light on this topic?

I appreciate any input!

rodrigfluis · Sep 13, 2019

Thank you for the reply! The PLC I am using is a GE VersaMax Micro Plus ICU200UDR164.

Lare · Sep 13, 2019

Welcome to forum.

You need first to only hours and PM / AM bit.

Then you can compare if hour is 4 or 2 set /reset if compare is true.

Look from manual page. 558 https://www.astor.com.pl › wsparcie › dokumentacja-techniczna › pobierz
There is SVCREQ 7 block.

Hours are MSB or LSB byte defending of format and are code to 0..23 format.
(LSB is easier to read, if you use integers, you can divide with 100 BDC format)
For MSB byte you need more math or Shifting commands for variable

Steve Bailey · Sep 13, 2019

The upper left node of the function block is the enabling logic. When it evaluates true the function is executed.

At the "FNC" node, enter the number 7.

At the "PRM" node enter the staring address of a block of six %R registers.

Before executing the function you must enter a value of zero into the first of those six %R registers. That sets up the function to read the PLC's time. You can also use SVC_REQ function code 7 to change the time, but that's not what you asked for. In the second of the six registers you enter a code to define how you want the time and date data to be formatted. Simplest is to use a value of 1, which calls for the data to be formatted as BCD with a two-digit year.

After executing the function the lower eight bits of the third %R register will contain the two-digit year in BCD format. The upper eight bits of the same word will contain the month.
The lower eight bits of the fourth %R register will contain the day of the month. The upper eight bits of the same word will contain the hour (0-23).

The lower eight bits of the fifth %R register will contain the minute. The upper eight bits of the same word will contain the second.

The lower eight bits of the sixth %R register will contain the day of the week (Sunday = 0). The upper eight bits of the same word will be blank.

rodrigfluis · Sep 13, 2019

Steve Bailey said:
The upper left node of the function block is the enabling logic. When it evaluates true the function is executed.

At the "FNC" node, enter the number 7.

At the "PRM" node enter the staring address of a block of six %R registers.

Before executing the function you must enter a value of zero into the first of those six %R registers. That sets up the function to read the PLC's time. You can also use SVC_REQ function code 7 to change the time, but that's not what you asked for. In the second of the six registers you enter a code to define how you want the time and date data to be formatted. Simplest is to use a value of 1, which calls for the data to be formatted as BCD with a two-digit year.

After executing the function the lower eight bits of the third %R register will contain the two-digit year in BCD format. The upper eight bits of the same word will contain the month.
The lower eight bits of the fourth %R register will contain the day of the month. The upper eight bits of the same word will contain the hour (0-23).

The lower eight bits of the fifth %R register will contain the minute. The upper eight bits of the same word will contain the second.

The lower eight bits of the sixth %R register will contain the day of the week (Sunday = 0). The upper eight bits of the same word will be blank.

This is exactly what I was looking for! Extremely thorough, and a lot more novice friendly than GE's User Manual.

Thank you all for the help!

sjohnson · Sep 13, 2019

Here is One example of what it looks like. Couple times a year have to sync the clock but other than that it works well for what it is needed..

rodrigfluis · Sep 13, 2019

Thanks for the example! I now have a much better understanding of the function!

Service Request 7

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