Putting a Comparator instruction in parallel with a contact in Machine Expert HVAC Ladder

[Anonymous user]

I'm fairly new to the world of Schneider PLCs and just wanted to put a Greater Than comparator in parallel with a normally open contact in Ladder logic like this.

But Machine Expert - HVAC doesn't seem to want to let me do that by directly dragging and dropping from the Operators and Blocks window and I can't seem to put a parallel branch around the comparator to add the contact.

Has any one come across this? What am I doing wrong?  🙄

[Bastian_Schmitz]

Hello TimK,

The Ladder editor in the Software are not the strongest available language.

I agree with you and see also no way to built directly the strucutre which you have in the other software.

But you could reach your goal in different other ways. 

1. You could split it into 2 Networks

2. Or you could use an expression instead the GT block together with an OR block

If you would convert a projekt from a Codesys based software to EcoStruxure Machine Expert HVAC you have also the oppurtunity to use the PLCOPenxml exchange. Normally you could export all your POU,FB,FC into an XML File. 

Later you could import them in EcoStruxure Machine Expert HVAC.

make a right mouseclick on top of the project table and choose import.

Select as format PLCOpen XML.

In this way you could import Ladder and Structure text POU,FB,FC.

In general I would advise you to use the FBD editor. This editor is much more powerfull then den LD Editor. 

In my personal opinion he is stronger like the version in codesys based solutions.

best regards

[Anonymous user]

Thank you for taking the time to clarify Bastian, I figured that the only way would be to "go around the houses" (split logic etc.) rather than take the unavailable straight route.

The project that I'm converting is actually built with SoMachine 4.3 with M251 and M221 processors as the target CPU's.

The reason for the conversion is the withdrawal of the M221 due to problems with its current CPU chipset. We have chosen an M172 PLC as a replacement, developed with Machine Expert - HVAC.

I like the idea of using PLCopen XML to convert code but I don't think SoMachine 4.3 can export to this file type. The last time I did an export, the code was saved as four .smbp files.

Many Thanks

[Bastian_Schmitz]

In Ecostruxure Machine Expert you could export to PLCopen XML I think that should also possible with somachine 4.3.

Here is a presentation to this Topic.

Convert Codesys3 to Ecostruxure Machine Expert HVAC 

best regards