1685.7 Interface Specifications[ 1 ] Interface Connector and Pin AssignmentCU-301The CU-301 has an RS-232C interface port (Dsub-9P).RS-232C Interface Port (Dsub-9P) on the CU-301Pin No. Signal Functions Signal Input/OutputCU-301 External device2 RD Receive data ←3 SD Send data →4 ER Data terminal equipment ready →5 SG Signal ground —6 DR Data set ready —7 RS Request to send —8 CS Ready to send —The input/output voltage threshold for the logical valued signal is listed below.Logical Value Input Voltage Threshold Output Voltage Threshold0 3V ≤ n ≤ 15V 5V min.1 -15V ≤ n ≤ -3V -5V max.CU-321The CU-321 has a Full-Speed USB 1.1-capable port (Series B receptacle).
