Communicatation cable for S7-300

[Twister_vdb]

Hi people,

I am the owner of a Siemens S7-300 PLC and after a few years of inactivity in the world op PLC's I decided to get back into it.

I have a ISA card and simatic software version 2 (to old) but can't use my card and neither can I use my bought software.

Is it needed to buy a cable from Siemens can I make a cable myself like you can for many other PLC's?

If somebody knows, drop in a note please.
I will post another message about a Saia PLC I have.

Thanks in advance,
Vincent

 

[jvdcande]

No Vincent,

you can't make your own cable for S7-300, because it's more than only a simple RS232-RS485 converter. It also performs some kind of protocol conversion and (in the case of a PC/MPI or a TS/MPI converter) a speed conversion. But you can buy the USB-MPI cable for about 200 Euro.

Kind regards,

 

[jvdcande]

I just received a PM from CBTussey, but since most of my reply can be of some intrest to others, I'm answering it here:

You mentioned that a USB/MPI cable can be purchased for approx. 200euro I think. What is the price of a RS232/MPI converter?

Well, the answer is that a RS232/MPI converter costs about the same. The drawback of this RS232/MPI converter however is that it's limited to 38.4kBaud at the RS232 side, while the USB/MPI converter is only limited to about 12MBaud. It's a huge difference, and since the MPI side is 187.5kBaud this means that RS232 is a serious bottleneck. At first I used the old RS232/MPI converters which at that time were limited to 19.2kBaud at the RS232 side. After that I installed CP5611's in my PC's, but the new DELL's are not high enough for these PCI-cards. Now I'm switching to USB and I'm expecting a lot from it (I'm waiting for the first delivery).

Kind regards,

 

[RRobbins]

My preference is the CP5613. It has a seperate processer and is better supported than the CP5611, costs a little more though. The part number for the USB cable is 6ES79720CB200XA0 and costs about $400.

 

[Twister_vdb]

Well, I ordered my cable today on the local supplier (CEBEO). After asking for advice to the technician-service guy he said he is happy with his serial cable.
At first I was in doubt because of my experience in the serial cable for the S7-200 at 9200. Now is the speed 38800 en should be fast enough for the type of person I am.
I just have the PLC for educational purposes only.
The price is around the €250.

By the way, the PLC is having a analogue I/O module. Could somebody post some site were they might have help on how to use (in the program) the inputs and outputs. I would like to experiment in damper control as were the damper motor is having a potentiometer inside them for acurate positioning.

Thanks already people,
Vincent

 

[flukie]

Now I'm switching to USB and I'm expecting a lot from it (I'm waiting for the first delivery).

JP,

Could you please let me know your experience of the USb adapter when you receive it?

Recently I had to buy my thirth CP5511 (PCMCIA) card as they always get broken on the connector side or getting to hot. (No I don't want to buy one of those $$$ field PG's with integrated MPI-port - I prefer to buy every year a brand new laptop instead of working for three years with a field PG).

I would like to know if the USB adapter is performing at least as fast at the CP5511/CP5611 especially for the monitoring and the status view of programs.

Grtz,
Stef

 

[jvdcande]

OK Stef,

I'm sure others will be waiting as well to know if these interfaces are better (faster) than the older ones.

Do you believe I just received a PM from someone who was told not to use the USB/MPI converter because they were too fast ? Maybe some salesperson with a lot of RS232/MPI converters laying around gathering dust .

Kind regards,

 

[flukie]

JP wrote

I'm sure others will be waiting as well to know if these interfaces are better (faster) than the older ones.

So, JP you allready got your cable?

Best regards,
Stef

 

[Valera]

Hi
and what can you talk about this subject:
ProTool->USB->Converter->MPI or DP of OP7-OP17. I am interested it because I khow that there was problem whith ProTool when there is'not COM1-COM2.

 

[Leonardo]

technical information

Hello Twister!
I read that you bought your cable at CEBEO! I thiks that is the best choice in Belgium! Me too I buy all my PLC stuff there!
Did you know that they got there own support people??
They got well trainend people who can answer all you PLC questions. They also can provide you with manuals or links where to find them!!

good luck!!

Leonardo