Comtech EF Data DD2401 VME - Manual (Page 72)

Rear Panel Interfaces DD2401 VME L-Band Demodulator Card Installation & Operational Manual
5-4 MN-VME2401 – Rev. B
5.3 EXT REF
The External Reference Input (J2) is supplied to allow the customer to phase-lock the
demodulator’s internal oscillator to an external reference. All internally generated frequencies
within the modem will attain the stability of the applied external reference.
This female BNC Connector accepts a 1.5 – 5 Vp-
p @ 50Ω. The frequency range of the external
reference is 1 – 10 MHz in 8 kHz steps.
5.4 SERIAL CONTROL & AGC Monitor (J3)
The Serial Control Interface Port (J3) is used for remote monitor and control utilizing Radyne's
RLLP Protocol. It offers a direct single connection to the individual demodulator. It is a Female
25-Pin D-Sub Connector supporting RS-232 or RS-485. Refer to Table 5-2A for Remote
interface pinouts and Table 5-2B for AGC Monitor pinouts.
For multi-drop communications, it is recommended that the J5 be used. The J5 connector multi-
drops all Remote ports connections allowing the user to connect to a single port. Refer to section
5.6 for additional information.
Table 5-4. Serial Control Interface Port (J3) - 25-Pin ‘D’ Female
P2 No. Pin No. RS-232 Signal Name RS-485 Signal Name Direction
A6 9 TXD TXD-B Output
A7 10 TXD-A Output
A8 16 RXD RXD-B Input
A9 3 RXD-A Input
A17 7 GND GND ---
Table 5-2B. AGC Monitor (J3) - 25-Pin ‘D’ Female
Pin # Signal Description Direction
5 AGC AGC Out Output
7 GND Ground ---
5.5 RX IN
5.5.1 L-Band
The Receive Input (J4) is the 950 – 1750 MHz Demodulator IF Input. It is a SMA (1) Connector.
5.6 Remote Port
The Remote Port (J5) is an RS-485 used for remote monitor and control of all demodulators. It is
a female 9-pin D-Sub connector. Refer to Table 5-5 for connector pinouts.