EMT or EPHT for project that needs to be developed using PCS7 V9.1?

Oreca

Hi,

An EMT is a CFC chart with a sequence control in it(SFC type). An EMT can be controlled by using global commands and statuses using technological IO. The EMT can be instanced in the project multiple times. With it, you can assign role assignments to control CM and also control of lower level EM.

 I have similar situation with this question.

i have experience working with SFC Type combined with process tag type (PTT) in the PCS7 V8.1 (non Simatic BATCH) continous process.

Now i have a project that need to be developed using PCS7 V9.1. This time i plan to use CMT instead of PTT, after i read the compendium C i realize now SFC type have evolved to two version either EPHT or EMT.

After read the documentation and trying some prototype i still can't decide which better to choose in my situation. Because i will not utilize SIMATIC BATCH, what your suggestion for my situation ?

Is it better i choose EMT / EPHT ?

many thanks.

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Split from What is the difference between EM and SFC-Type?.

Hi Mr Gun,

You can refer this below query 

EMT/EPHT use case

EPHT will be used majority with BATCH application.

Hence, you can go ahead with EMTs for your project!

Please find the attached doc for understanding the use case of variants.

Hope it helps you! 

Oreca

Hi,

I highly suggest using the new concept EPHT/EMT. The concept is the new standard and the biggest advantage is the synchronization that is a lot better than with PTT.

With PTT you can do bulk engineering, but when the Process Tags are created, synchronization is very limited, changes cannot be synced to the PTT ending up deleting the Process Tag and generate again, but all connections will get lost.

The EMT/EPHT can be synchronized via a new editor called Plant Types (XMLTRANSFER). When a change is made like adding an And04 block to the EPHT/EMT, after synchronizing, the instance EPH/EM will get this And04 block as well.

The EPHT/EMT can also be used with regard of Plant Automation Accelerator (since newest version). 

In EPHT/EMT you can add lower level EM as well, so if you have like a EPHT, you can control lower level EM as well which makes engineering very easy and enables a lot more options.

Apart from this, CM can be controlled as well. In a CMT you can create commands like SetOpen and statuses like IsOpened to control a valve, you create a role in the EPHT/EMT and use the role to control the valve in the SFC. There like placeholders. After the EPHT/EMT is instanced, you can attach the real CM to the configured role and your done. 

An EPHT/EMT always has an SFC type, you can set the SFC to class: "EOP" or "EPH" in order to use it in SIMATIC BATCH, if you choose "None", it won't end up in BATCH, so BATCH is not necessary at all. 

 Hi Oreca,

Thanks for the clear explanation. Yes the action / condition (technological) is a helpful tool for standardized the action and status reading which if done in original method will prone to human error (forgot to reset / set; etc).

i also decided to go with EMT for my case since i will only use the direct control of CM without any control from higher level.

However, i also have a concern for synchronization. I also still learning and reading the guide of 

CMT Synchronization

when i tried to apply it to synchronize the EMT.

this is my step:
1. Open EMT type in project library (plant view)

2. Open the SFC type from the chart. (right click Open SFC Type)

3. Finish editing the steps.

4. Synchronize EMT via plant type. 

5. Result synchronize: Warning (different source and target) with red triangle

6. open the instance of EM and open the SFC type checked that the steps added not updated.

kindly help to advise the good practices.

many thanks.

Techno_Taru

Hi Mr Gun,

You can refer this below query 

EMT/EPHT use case

EPHT will be used majority with BATCH application.

Hence, you can go ahead with EMTs for your project!

Please find the attached doc for understanding the use case of variants.

Hope it helps you! 

 Hi Techno_Taru,

thanks for the reply.

yes, i also think EPHT will be suitable for BATCH application from your explanation. From the diagram it can be used to control more EM.

 Hi

Oreca

 Hi, if you have several EPHT it is even possible to control the same lower level EM, from different EPH. That is not possible if you have EMT that control lower level EM.

Unfortunately Siemens confuses the user because they use name: EPH that is normally an equipment phase equivalent to the RPH in Simatic Batch. But doesn't have to be.. 

 i see..

it's more like safer choice for my condition to use EPHT "in-case" i will need controlability to lower EM.

Oreca

For the synchronization:

Make sure you synchronize the SFC from the Charts folder and not from Blocks folder. Otherwise the synchronization will fail. The SFC can be updated through Charts->Update block types.

After that you can synchronize the EPHT/EMT via Plant types of you have made any changes to the CFC of the EPHT/EMT.

This is my summary CMIIW

Modification done in master library EPHT  or EMT :

1. Adding CMT or EMT role and assignment

2. Add connection or block in the template chart

3. Add status / command in the template.

--> synchronize via plant type --> done

Modification done in project chart folder

1. Editing SFC type (creating steps, transition, etc)

2. update block type in the chart ? (please see my screenshot) i can't find my FB1026 / FB1027 / FB1028 in the block type offline or chart folder

3. Copy back SFC type edited in the project chart folder back to Master data library ?

Oreca

Hi,

You can easily convert from EPHT to EMT and vice versa by right clicking the object and hit convert in the TIO editor, but at the moment there is a bug that instances are not updated so all instances need to be done also..I hope they fix it soon.

Please always work in the master library. Do not work on SFC in the project. Updating SFC block type must be done from the Charts folder in the master library to all projects resulting in a full compile and download change.

To update the SFC type: select master library charts folder (Component View) and select the FB, go to Options->Charts->Update block types and execute the change.

 Hi Oreca,

Thanks, now my doubt is cleared.

EPHT and EMT are interchangeable and it's great.

Step for updating the block type from the master library is also clear. When i working with PCS7 V8.0 and PTT usually i directly edit the SFC Type in the chart project folder (component view) and archive back the type to master data library only for backup purposes.

I wonder Siemens should add this necessary step more clear in compendium. To help many new user have same perspective to work on.