Comtech EF Data DM240XR - Manual (Page 74)

DM240XR High-Speed Digital Modulator Rear Panel Interfaces
MN-DM240XR– Revision 13 5–4
5.5 External Reference (Input)
The External Reference Input (J8) is supplied to allow the customer to phase-lock the modulator’s
internal oscillator to an external reference.
This female BNC Connector accepts a 1.5 – 5 Vp-p @ 50 Ohms. The frequency range of the
external reference is 1 – 10 MHz in 8 kHz steps.
5.6 Remote Port (I/O)
The Remote Port Interface (J4) can be used for the monitor & control functions of the unit. The
physical interface is a female 9-Pin D-Sub Connector. This bi-directional port complies with
RS-485 Electrical Specifications. Refer to Section 7.6 for protocol and programming details.
Pinouts are listed in Table 5-1.
Table 5-1. J4 - RS-485 Remote Control- 9-Pin ‘D’ Female
Pin No. Signal Description Direction
1 Tx (B) Transmit Data (+) Output
5 GND Ground ---
6 Tx (A) Transmit Data (-) Output
8 Rx (B) Receive Data (+) Input
9 Rx (A) Receive Data (-) Input
5.7 Terminal Port (I/O)
The Terminal Port Interface (J1) can be used for the monitor & control functions of the unit. The
physical interface is a female 9-Pin D-Sub Connector. This bi-directional port complies with
RS-232 Electrical Specifications. Refer to Section 4.8 for terminal interface details. The pinouts
are listed in Table 5-2.
Table 5-2. J1 - RS-232 Terminal Port - 9-Pin ‘D’ Female
Pin No. Signal Name Description Direction
3 TxD Transmit Data Output
2 RxD Receive Data Input
5 GND Ground ---
7 RTS Request to Send Output
8 CTS Clear to Send Input