r_trig-detect-positive-signal-edge-s7-1200-s7-1500

- Edge (positive / neg) can be write in  SCL : 

I have make a FB for Edge because there is not a standard function can be write in SCL. Can be a standard thing ?

 

MBTCP calls for remote device data follow the Modbus protocol - once MBTCP call for each remote read where you give the starting point and number of registers to read per call.

Once you have your own FB to handle multiple MB register or other values within the same MBTCP device, you should add it to your global library so you can reuse it - because it suits _your_ specific needs.

If you have an HMI DB where all the HMI / PLC tags reside (in the PLC), you can insert a section for constants, and in the startup OB (OB100), map your constants into "HMI".Constants.Constant1 ... and so on (using MOVE).

You can create a UDT, maybe named, "TagWithLimits_UDT".  Then in your "HMI" DB, you can have lots of tags of datatype "TagsWithLimits_UDT".. where:

UDTs:
TagsWithLimits_UDT: Struct
  Value : Real (or Int/Dint/UInt/..)
  UpperLimit : Real (or Int/Dint/UInt/..)
  LowerLimit : Real (or Int/Dint/UInt/..)
---

OB3n Timed Interrupt OBs already perform the operation you need.  However, it does take some creativity on your part to create the proper code architecture to make it happen.

For example, let's say you have some predictable but lengthy calculation you wish to perform once every 10 sec, but will take up to 5 seconds to complete.

To reduce overall scan time, you need to break up the calculations to perform let's say 5 ms worth per OB3n call - let's call it OB30.  For a ~5000ms overall calculation, calculation 1/1000 of the total calculation per call means you need 1000 calls distributed over 10s.  So, call OB30 every 10ms, which is 100 calls per second over 10 seconds, for 1000 total calls.

Now, inside OB30, break up the large calculations with a tracker that keeps track of the call count, which starts at 0, on first call, increments "count += 1;", and when it reaches 1000, resets back to 0 at end of OB30.

Inside OB30, each chunk of the overall 5s of calculations gets broken up into proper ~5ms chunks.

Now, the most important part is to configure OB30 Properties.  Do not allow that OB to queue up, and to generate a diagnostics buffer entry if it queues up too many (1 in this case).

Once OB30 queues up even once, your PLC code runs the risk of never getting finished in time and watchdog faulting.  The reason for diag buffer entry is to know when a particular section of the calculation has taken too long (by ~50-80%).  Then you can peel back how much work gets done by 50-80%.

I suspect you only need the diag buffer entry when loops end and start into the next phase of calculation looping.

For RT-INFO, you are always fully capable of adding your own input parameter to any FB/FC you create that informs that block about what called it - be in a cyclic OB (OB1, OB123, OB200, OB2000, for example), or interrupt OB (diagnostics or cyclic or some other type of specialized OB). Once you have it working to your satisfaction, meeting your specific project's needs, you are urged to add to your global library for reuse with ease.

Do you mean HMI based data logging?  I think they call them Trends on Siemens HMIs if you want to visualize that historical data.

A.Brun

Hello here.

There a lot of improvement i like to have to TIA portal PLC/HMI system :
[...]

- No code for simple Modbus TCP :

A lot of PLC brand have entended modbus that only need to set data table. I don't realy understand why in 2025 we need to write code when we have more than 1 data zone in modbus TCP client.

- Can exchange constant between PLC and HMI or project constant :

There is not HMI constant, i like this function for de/activate settings in my project. I already have a constant in PLC for that purpore, i like to link PLC and HMI constants.

- Can transmit limits on tag to the HMI :

when i drag/drop an Data from PLC to HMI, i like a way to also link min/max from plc (can be constants or others datas). in that way we can secure in plc with the LIMIT function and also show that is the min max setting.

[...]

- New type of OB that can run 1 time eatch 10s (or minute or hour) that is limited to 10ms pear OB1 
It allows big calculation or strings traitment (i need to send MQTT and averages calculations on big DB. Ffor that, I need spécial thing on code to separate calls for the watchdog don't hit 5000ms)
Also, i will like if i can have one part of the code that run in OB1, OB100, OB30 ? 

- RT-INFO give information about the selected OB.
i will like an bloc that give actual type of OB (main for general process, Cyclic interrupt for average calculation and PID, Startup for reset, etc ). We can put that type of info inside FB that auto execute eatch part of code depending of the OB called. (actualy i need to have a extra input on eatch block and to be complemented)

/edit 10/06/2025

- Add data to HMI ‘Historical data’. maybe there an parameter in the PLC to automatically set data to an historical data ? 

RD_SINFO maybe?

- RT-INFO give information about the selected OB.
i will like an bloc that give actual type of OB (main for general process, Cyclic interrupt for average calculation and PID, Startup for reset, etc ). We can put that type of info inside FB that auto execute eatch part of code depending of the OB called. (actualy i need to have a extra input on eatch block and to be complemented)

Elaborate, what kind of settings you have in mind and what it means to deactivate them.

- Can exchange constant between PLC and HMI or project constant :

There is not HMI constant, i like this function for de/activate settings in my project. I already have a constant in PLC for that purpore, i like to link PLC and HMI constants.

Did they already add this to S7-1200 G2 PLCs? 

A.Brun

Edit on the 1st topic 

(add request to be enable to use Program_Alarm in S7-1200 serie)