Which RS-232 data lines are active? Find out with this RS-232 mini tester. It makes troubleshooting easy by helping to check interface connections, equipment, cable problems or failures. Model 9PMTT RS-232 mini tester is designed to connect with any RS-232 interface. The tester may be left in the line permanently. It is transparent to data transfer. Bright red or green LED signals clearly show which lines are active. The LEDs’ color indicates Negative or Positive voltage (red meaning Negative; green meaning Positive).
