Establish comunication between PC and Simeas P

Hi to all, expert,

I've a problem with a Simeas P multimeter, this was install from another company and now the client ask for some modification.

I read something about the configuration and found out that u need a normal seriall cable and a converter 232/485.

So i've a moxa uport and serial cable connected with pin 8 -; pin 3 + ; pin 5 gnd.

i've changed the interface of the multimeter from profibus to PC 485, and i try to connect but with out seccuces.

Someone could help me? any suggest?

Thanks to all.

Ragards

Duccio.

Hello Duccio;

The Simeas P multimeter was produced by a division of Siemens, now called Siemens Energy, that is distinct from the IA&D division that supports this forum. The Simeas p has been renamed Sicam P by Siemens energy.

If you do not want to use Profibus and you want to connect over RS-485, you must select a protocol that is supported by the Simeas/Sicam P multimeter, and that leaves you with only one choice: Modbus RTU.

Here is a copy of the Modbus manual for the Sicam P:

Power Meter SICAM P - Siemens

It will indicate how to connect to the multimeter using Modbus RTU over RS-485, and provide the register mapping you will need to read/write to the unit from your PC. If all you need to do is modify the value of some registers, you could do it with a Modbus simulation program, such as Modscan 32 (there are many available online freely-downloadable).

If you have not worked with Modbus RTU or if you need a quick refresher, I recommend you take the time to read this excellent thread by member smiffy, which many here have found instructive and helpful:

Modbus General Description

https://support.industry.siemens.com/tf/ww/en/posts/66876/

Hope this helps,

Daniel Chartier

Hi dchartier,

Thanks for your explanation, i will try to connect in modbus, the only dubt i still have is regarding the cable connection, because i havn't possibility to provied the 5V.

I will let you know.

Tanks.

Duccio.

Hi,

in the product Information of Power Meter you can read,

"The package includes the Windows
Parameterization, a Connecting cable, a RS232 / RS485
Converter and an AC adapter.
About the converter is the
SIMEAS P with a commercial
Notebook or PC with a 9-pin
D-SUB connector connected."

Regards,

Towome

Hi, 

My problem is that i'm on field, and 'havent the right cable, so i think that could be possible build by my self.

Now i have a normal laptop with a RS232.

I'll try to buy some 232/485 converter with a +5v power supply.

Do you think could be possible?

Regards.

Hello Duccio;

In the manual of the Sicam P Modbus suggested earlier, you will find the following connection diagrams (see attachment).

Follow the schematics to connect a 5V power supply to pins 6 (VCC) and 5 (GND) of the 9-pin Sub-D connector. And think of adding the terminating resistors at one end of the bus for network stability.

Hope this helps,

Daniel Chartier

Hi Daniel,

Thanks for your support, so you confirm that is not possible comunicate only with the pin 3-5 and connected, i need also to connect the pin 6 with 5 volt, it is correct?

Regarding the resistor i need to connect as well?

Thanks.

Duccio

Hi,

I try to connect with the moxa converter 232/485 with only pin 3,8,5 connected, whitout provide power and was ok. 

Only different like before is that i've changed the baud rate from 152000 to 19200.

At the end my configuration for establish the connection was:

Moxa Uport 232/485 configured in a COM1 liake 485 2 wire.

on the multimeter address xy, 19200, N, PC485

On the software configuration address xy 19200, without check "with mirrored RS 485 adapter"

Regards, and thanks to all.

Duccio

Hi Duccio, i have some questions for you:

1 - have only connect the pins 3 (A), 5 (Gnd) and 8 (B)??

2 - have used the terminal resistances?? (two by 390ohms and one by 220ohm)

3 - the Sicam is powered from own power suplly?? (from H1 - H2)

4 - how change the port mode from Profibus to RS485?

Many thanks

Mattia F.

Hi Mattia,

Here the answare:

1- Yes i've used only the pins 3 (A), 5 (Gnd) and 8 (B).

2 - No, any terminal resistance.

3- I don't understand what you mean, the sicam has powered form the internal 24Vdc.

4 - In the SIcam press Enter, will appare the main menù, basic setting, interface.

     Inside interface there are the bus parameter.

Hope will help.

Regards.