RS 232 Serial Devices

[Former Member]

Hi,

We have a requirement to communicate with serial port devices (engravers etc.) on the shop floor. We are evaluating 2 different options -

i) Kepware U-CON

ii) Transceiver (Power over Ethernet to RS-232)

Can somebody comment on the pros and cons and what is a recommended approach, particularly with MII as the middleware?

Regards,

Chanti.

[Former Member]

As Steve mentioned in his reply,

We have used the following in combination and works fine.

1. Kepware U-CON for device driver related development

2. MOXA NPort 5600 series (16 port). This you can be configured to connect with RS-232, RS-485 & RS-422 types of devices.

The solution is online and performing well for the past two years.

[Former Member]

I've used Kepware U-CON and its a pretty rock solid Serial to OPC driver.

For serial to ethernet, I've used Digi One SP's they are great (about $100 a piece, less for bulk) http://www.digi.com/products/serialservers/digionesp.jsp#overview

They are rock solid and are the only one's that I found that allow for multiple server's to talk to the remote devices without custom coding (very important in redundant SCADA applications) This one is a point to point but they make other models that have multiple ports to single ethernet. I prefer point to point because that gives me less single point failures.

[Former Member]

I've got a DIGI ONE SP - device to communicate with.

Do you have ABAP-code examples to communicate with it?

Thanks!

André

[former_member196557]

Chanti,

Kepware U-CON turns the connectivity from MII into OPC tag queries. Depending on the complexity of the serial interface, the development could be significant. You will still need an Ethernet - Serial adapter at the tool to connect it to the network. You can also completely test the OPC interface to the tool with the OPC Client without involving MII at all

I am not aware of an easy way to get MII to communicate directly with a serial data stream. Pco does not yet have a bi-directional Ethernet Socket Agent and I do not know if UDS can do this or not. Maybe a custom action block in MII do do direct Ethernet socket would be a possiblility.

- Steve

[Former Member]

Thanks Steve. Do we need as many ethernet-serial adapters as there are the devices?

[former_member196557]

Chanti,

Not necessarity. Several vendors make multi-port Ethernet-Serial interfaces and terminal servers. You will need to determine how far the cable run would be from the device to the interface, and whether the run is RS-232C or RS-422 as well as the baud rate. All these factors will determine what the maximum distance the cable run from the interface to the tool can be.

B&B Electronics, http://www.bb-elec.com, has a good selection of devices.

- Steve