Siemens Upload/Downloading help

[kbradray]

I am sure that I seem very stupid at this point for asking such an elementary question. I have for the most part only worked with AB products. I have been asked to make some modifications to a Siemens CPU314C-2DP processor. I have been able to set up the PG/PC interface and upload the program existing in the processor. My questions come when I try to monitor, change, and download program modifications. I think I have read somewhere that when you download to the PLC it goes to a CF memory card and is read sometime by the PLC to check for program changes.

If some of you could walk me through a simple how to monitor, online edit, and download directly to the PLC, or explain how PG to CF to PLC works I would greatly appreciate the help.

 

[panic mode]

when you download changes, they go to MMC. if someone changes parameters from HMI for example, it will work but to should keep in mind to transfer that to MMC at some point.
there is no real online editing (at least not like what you are used to), but you can start making changes even to monitored block (it will stop monitoring) so when you are done with changes, you can transfer them to plc.
to start monitoring, open block and click on monitoring icon (glasses).
note that monitoing is a bit awkward:
- refresh is usually horribly slow even on fast connection, and not everything displayed is updated (for example if ladder, one usually can see only one or two rungs, if they are large, you will be lucky to monitor half of rung). workaround is to keep clicking on different places until software starts monitoring part you are interested in.
- monitoring is inconsistent for different types. numeric values are shown as processed by plc so same address can show bunch of different values on the same screen and at the same time. if particular instruction is not executed for example (because condition in front of it is off for example), the numeric value is not even shown. bits (booleans) are monitored differently (like on other plcs).
etc.

 

[kbradray]

Thanks

Thanks for the quick reply. How do I get the PLC to read the MMC after download?

So if I am understanding correctly I make the change to the program and download. The download is saved to the MMC. At what time will the PLC see the changes (when will it load the MMC).

Can I make the PLC load from the MMC?

 

[L D[AR2P#0.0]]

STOP. Ask for the back-up of the program first. Compare the back-up with what is in the processor and proceed from there.

If you upload and modify you will lose all comments (if there are any to start with)

 

[kbradray]

No Comments available

The program that I am working with came from the PLC itself. I had to upload the Program from the processor. The vendor will not give me any of the symbol data, so I am working from the schematics. When I started my Siemens experiment I began by setting the PG/PC interface (MPI) and uploading the program. I am trying to make some elementary changes, but I am not having any luck. This lead me to guessing. I have been able to monitor some IO to make sure I am looking at the schematics correctly. I was just trying to learn if when I download back to the PLC are my changes seen imediatly.

Ken

 

[L D[AR2P#0.0]]

In that case good luck. When you download a block, the change will take effect immediately.

 

[geniusintraining]

Hey Ken,

I have many CPU's... I can loan you one or you can buy one if you want to learn on something that will not matter if you screw it up...

I only have one DP2, but you can play with the MPI on one of the others

If you are interested send me a PM or email

Mark