For decades we’ve relied on our laptop’s trusty serial port or PCMCIA slot to communicate with legacy A-B devices. But when our old laptop dies, or our new one arrives, its very likely it with have neither a serial port or PCMCIA slot. This is when most of us begin thinking about moving to USB.
The good news is today most all legacy A-B networks can be connected to with the use of USB cable. The bad news is those USB cables which replace the expensive PCMCIA cards of the past are just as expensive as those legacy products were when they came out back in the 90′s.
Even though new laptops don’t have a nine pin serial port, most of us still have many devices in the field with them, so this cable is one of the first you’ll want to consider buying. Rockwell makes the 9300-USBS, which is currently at rev 3 (aka series C) and is fully tested with all A-B products and serial cables. It’s also one of the few USB serial cables on the market which also supports RSLinx Classic’s “auto configure” option for finding the baud rate of the serial device connected. However, with a list price of $144, that may be a feature you’re willing to give up. In the past I’ve purchased USB to serial converter devices which looked identical to the 9300-USBS for one tenth the price and they’ve worked well except for the lack of support of “auto configure.” If you do buy a third party USB to serial cable I recommend keeping the receipt and testing it right away as you don’t want to find out it’s not compatible when you need it the most.
USB to DH-485: 1747-UICC13
If you need to connect to a SLC-500, SLC-5/01, or SLC-5/02, you’ve likely used the large and unwieldy 1747-PIC in the past. The good news is it’s replacement is considerably smaller, and supports DH-485 via RS-232 and RS-485. However, with a list price of $417.00, and native support for 19.2K (9600 support can be added with a firmware patch from Rockwell found here) it’s not the biggest bang for your cables bucks. You also need to be careful not to just plug any Ethernet patch cord into the RJ-45 – it’s a known issue that using an Ethernet cross over cable to connect from the 1747-UIC to a SLC-500 will permanently damage this cable. This is why I’m recommending the bundle here, the 1747-UICC13 as it contains the 1747-UIC and the properly wired 1747-C13 cable.
Note: Many of my clients have forgone the official Allen-Bradley DH-485 USB cable, and instead have used a third party 1747-UIC cable which has the RJ45 and 9 Pin D Shell cables attached, and costs a fraction of the price. If you’re interested in this third party cable you can find it on Amazon using the link provided below:
USB to DH Plus (DH+): 1784-U2DHP
The u2DHP is a replacement for both the PCMK and PM05 /06 cables (1784-PCMK, PCMC, PCM5, PCM6) as well as for the many iterations of the KT card (1784-KT, KTX, PKTX, PKTXD) when used in programming stations or PC’s. It makes connecting to Data Highway Plus via USB possible, although it only has the 8 pin circular mini din connector found on the SLC-5/04 and New Platform PLC-5’s. And with a list price of $2780 this device is strictly for the “have to have” crowd.
Note: If you need to connect to a Classic PLC-5, or any Data Highway Plus product with a 9 Pin D Shell, you’ll need a separate adaptor to convert the 8 Pin Mini Din. Grace Engineering makes one such device, PN# C-ABDH-Adapter, which you can find detailed on their website using the link below:
USB to DeviceNet (DNET): 1784-U2DN
The 1784-U2DN is a replacement for the 1784-PCD and 1770-KFD, and allows for connecting to DeviceNet via USB. Support for this hardware begins with RSLinx 2.51 with RSNetworx for DeviceNet version 8. The 1784-u2DN lists for $1,610.
USB to ControlNet (CNET) 1784-U2CN
The 1784-U2CN is a replacement for the 1784-PCC PCMCIA card, and comes with a ControlNet NAP (RJ-45) connection. The U2CN lists for $1,930.00
The 1203-USB cable is as universal as a programming cable as they come supporting Scanport, DSI, and DPI A-B Drives. This includes, but is not limited to the 1305, 1336 Classic, 1336 Plus, Plus II, Force, Impact, PowerFlex 4, 4m, 40, 40p 400, 70, 700, and 520 series. It comes with the device itself, a USB cable, a 20-HIM-H10 cable, and 22-HIM-H10 cable, and lists for $358.00
Update: Additional third party cables available from Amazon.com
Hopefully you’ll find this listing of A-B USB cables helpful. If you have any experience with these cables that you’d like to share please do so by using the “Leave a reply” form at the bottom of the page.
By Shawn Tierney