Micrologix1500 and RSlogics500

[Eric142 0]

I am connecting to a Micrologixs1500 using RSlinx with the DF1 RS-232 Driver. My laptop does not have a COM port so I am using a USB to serial adaptor (Airlink 101). The problem I am having is the computer constantly disconnects from the PLC when in the online mode. This is very frustrating when trying to troubleshoot something. Anyone know why this is happening, I have had this issue with more then one laptop so I am gussing I have some setting wrong but don't know what it is. Thanks for any help, if you need more info let me know. Thanks again Eric

[ElecPneuGuy 1]

Did you let windows automatically install your USB driver? I had problems with my USB driver when windows searched for the driver and automatically installed it. I had to use the install disk that came with my USB to Comm port adaptor. Thats my first guess........

[Mickey 71]

Not all USB to Serial adapters work. A "Keyspan"USA 19HS does. See link below ( scroll down right hand side) http://www.plctrainer.net/ You also might try unchecking "Autobrowse" after it connects, that sometimes helps. Edited 9 Apr 2010 by Mickey

[Eric142 0]

Have not tried that will do.

[sandeep424 0]

Hi Eric I am also doing similar kind of work. But I am not connecting PC to the Allen Bradley Logix 500 PLC but I am trying to connect an external device(FPGA) to the PLC using an RJ - 45 serial cable to the RS-232 port of the PLC. I am very new to these PLC's and I want a small favour from you. Can you please help me in understanding of what changes hsould be done to the PLC so that it detects my device and then what program should I write to the PLC for my device to receive data from PLC. I know that the RS-232 port talks with the help of DF1 Protocol, so how should I implement this protocol in my device , how should i understand the ladder logic program of the PLC, what instructions should I add to the PLC program so that it sends the data (the same data which it sends to modem) to my FPGA device. Could you help me with any papers which can help me or any examples or suggestions or any hints. This will be a great help to me. I am sorry to suddenly interrupt your thread and ask you a question instead of helping you with your problem. As I am very new to this area, I have a very little knowledge of your problem and I feel sorry for not helping you. But please help me with this. Basically I am expecting some list of steps to connect to connect to PLC, PLC detecting my device and communicating with my device. Thanking You -Sandeep Edited 9 Apr 2010 by sandeep424

[BERING SEA SPARKY 0]

Thanks for the advice. I was haveing a similar problem using a 1747-uic usb to dh485 interface converter. constantly loosing connection to nodes on the network. after reading your post, i waited for all nodes to be found then unchecked the autobrowse and now i can stay connected all day with no problem. Such a simple fix, thanks for the info.

[Mickey 71]

Your welcome Edited 15 Apr 2010 by Mickey