TCP communication

[charlesdes 0]

Hi, I work on a projet with a microscan visionHAWK smart camera. This camera can send a string through a tcp port on Ethernet/IP network. I try to read this string in rslogix 5000 for my AB compactLogix L23E PLC. Is it possible to read a string with the message instruction? In the instruction help, I see that it can read and write integer and real. Also, I would like to know how I can specify a port. Exemple : the IP adress of the smart camera is 10.1.105.247 and it sends the string on the 41211 tcp port, do I have to write 10.1.105.247:41211 in the path of the message instruction? Thanks for your help Charles

[Ken Roach 194]

I think you've unfortunately fallen victim to the confusion between application protocol and transport protocol. Rockwell Automation's name for the ControlLogix application protocol is "EtherNet/IP", for 'Industrial Protocol". This is how Allen-Bradley logic controllers exchange data with one another and scan cyclic I/O connections. Despite the fact that it uses Ethernet, and it uses Internet Protocol (IP), the ControlLogix family doesn't necessarily support all the other application protocols in the world, like FTP or SNMP or even just "send a string through a TCP port". ControlLogix always uses TCP Port 44818 and this cannot be changed. You might be able to make such an interface with one of the "web services" modules, 1756-EWEB or 1768-EWEB, or with a module from Prosoft. The current generation of 1769-L23E controllers do not have this feature. The newest generation of 1769 controllers, called the "5370" series, will have the "web services' open-socket feature built in. The VisionHAWK website refers to "industrial protocols" but I haven't seen anything specific yet. MicroScan technical support has a pretty good grip on the A-B protocols; I worked with them in detail on the DeviceNet interface for one of their barcode readers.

[charlesdes 0]

Thanks for your reply, So what I understand is that it is impossible to read the string of the camera without a 1756-EWEB. I thought it was possible with the message instruction. The microscan's vendor said me it was compatible with AB plc when I bought the camera but he didn't said me I had to buy a communication module... I've try to read the string output of the camera with telnet in it works, so I just need to make the PLC reads this. Thanks a lot for your help.

[b_carlton 61]

Before we buy anything that says that it is 'compatible with xxx PLC' I ask for a typical setup diagram and a working commented example program. I know, it doesn't help in this case but a warning ...

[Ken Roach 194]

Microscan is ODVA member number 1095, so the company does build EtherNet/IP products that are compatible with ControlLogix. But I'm not certain that this camera is one of them. The literature I read briefly only refers to communications over "RS-232 and Ethernet", and alludes to "industrial protocols". But I didn't find any reference to EtherNet/IP nor to the TCP port you described. Hopefully Microscan has some additional information for you.

[charlesdes 0]

The camera can communicate by serial link, that is what I will do to read the string but I will contact the vendor before to be sure it's impossible by Ethernet. Thanks again for your help and I will use the tip of b_carlton in the future

[BobLfoot 301]

If you can get serial out of the camera then the 1734-ASC module and a 1794-ENT module can combine to send the serial data over ethernet to your plc. Just another way to skin this cat.

[charlesdes 0]

I talk with someone today who told me that it is true that only new generation of compactLogix can open socket. But, he told me I should be able to map the camera using the IP address. I just need to specify, in the message instruction path, that I coming out of the controller, then from the controller I reach towards the device. Edited 20 Feb 2012 by charlesdes