Check Signal Cable
August 12, 2011 at 9:20 pm | Service,
If you are experiencing skips in your plotters movement, or intermittent failure of the pen or cutter, you may have a signal cable that has a faulty or broken connection.
To check your cable, do the following:
- Unplug both ends, and put both ends in a vice, or something to keep them stationary while you take measurements on the pins.
- Set your multimeter to continuity mode, or resistance measurement mode on the lowest setting.
- Now you will go through each set of pins, and measure the continuity between them. (see image)
your multimeter should read a very low value (under 100 ohms), or beep if the pin you are testing is continuous.
- If in testing the pins, you read a high resistance, or an open circuit, then the cable is faulty and should be replaced.
To test if signal from the computer is reaching the pen/knife functions, do the following:
- Plug one end of your signal cable into the computer
- Put the other end of the cable in something to hold it stationary while you perform some measurements.
- Set your multimeter to measure DC voltage, and set the voltage range to the smallest setting that is over 5 volts.
- with the pen and cutter both set to their normal up position in Plotmaster, test between ground (pins 18-25), and the pin that controls the cutter (pin 9). see image.
The pins are numbered in very small numbers on the plastic that they protrude from.
- You should read within 10% of 0 volts.
- now, toggle the cutter down in Plotmaster.
- now, repeat the measurement process (steps 4 and 5), but this time you should a voltage within 10% of 5 volts.
- To test the pen up/down signal, repeat this process, but instead take your measurements between ground and pin 8 (pin 22 if you are running PM32).
- If, for either of these measurements you do not measure 5 volts when the pen/cutter are down, you may have a bad signal cable, or a problem with the connection with your pc.