RS Logix 500 serial comms problem

[Aftech 0]

Hi My laptop has no serial comms port. I am using a Moxa USB to serial converter. Sometimes it works fine but sometimes not. I don't understand why. At the moment I have a ML1000 plc. I go online, but as soon as the outputs comes on and the 3phase motors starts, the comms fail. I then have to shut down RSlinx and restart again and do the whole auto config again. Then the comms work but as the motors starts the comms fail. Please help me ? Thanks.

[Toot Uncommon 0]

What exactly happens when it fails? Does the usb device drop out of Windows, or do you only have to restart the driver in AB software? We also have had that issue with usb to serial. One of the engineers here has a new laptop like yours. In our case the driver has to be reconfigured in rslinx--once about every minute and a half of use. Since it isn't my laptop, I didn't troubleshoot. I recommend you reconfigure the driver in rslinx and set the baud rate very low--as low as your usb-to-serial adapter will allow. You'll need to set your usb-to-serial adapter lower first, then do the driver. Set it as low as possible, then if it works, you can raise as high as will not cause drop outs. If that doesn't work, they have pcmcia to serial devices (google "pcmcia serial"). I would think they'd be less susceptable to noise like this. Though you may not have a pcmcia slot either...

[Armadillo852 25]

I have a serial port on my laptop that works well. I have a question, does this Allen Bradley play nice with this pcmcia card? I know from the past AB did not like to share slots.

[plcdp 11]

I use the PCMCIA card to communicate with our AB stuff and I haven't had any issues. In my experience so far, this device has been the only AB com unit I've used that has "played nice". I used to use the PIC driver and any time I needed to communicate with another brand of PLC I would have to un-install the PIC driver and reboot the system to establish comms with the other PLC. Hope this helps some, plcdp

[slcman 9]

I tried many USB to serial and never got good result. I used PCMCIA card from Quatech ( www.quatech.com ) and it's working as a native serial port exept for PIC module. Now I use Express Card from quatech again and like PCMCIA, it's working like a native serial port. PIC module doesn't work with PCMCIA and ExpressCard but 1747-UIC can replace that old big box most part of the time (when baud rate is 9600, 1747-UIC doesn't work PIC module must be used).