#How to make a serial loopback cable download#
If the loopback test fails, the port may be defective. Download my Interface Cable Loopback Tester and follow the directions to test your cable. If the loopback test is successful, the port is physically OK.
Without the loopback, you should not see the character echoed. Now remove the paper clip from the port and type a character. You should see the character echoed on the screen. Then unplug the connected device and plug in the disconnected one, without rearranging the cabling otherwise. For example, a loopback device may be attached directly to a computers. Performing a loopback test is generally a multi-step process. Technicians use this method to quickly test whether data ports, cables and connections are working. Power the devices on and make a note of which LEDs are lit. Loopback testing is commonly performed on serial, network and telephone links. Before powering on both devices, unplug just one of them. Perform a loopback test: Type any character. Given the cable that I believe will work, connect the cable, LED box and two devices all together.i buy rs-232 and connect pin 2-3 and pin 7-8 to make a loopback.
#How to make a serial loopback cable windows#
Make a Telnet or proxy connection to the problem device. can you capture some lines with a easy serial terminal programm like windows hyper.At the remote site, unplug the serial cable to the NOC and loop the port's TX pin to its RX pin with a paper clip or screwdriver. First, verify that the device at the remote site is OK.Note: you need two techs for this: one at the NOC and another at the remote site. Troubleshooting a problem serial connection between a remote site and the NOC is not too different from troubleshooting a local serial connection, as described in Section 4, "How to Test RS-232 Connections with a Screwdriver or Paper Clip."