The RS-232 Serial Cables and Connectors:
The Multi-Function LD Card's RS-232 port is always the lower port on its interface module. On the ME758C models it is a standard DB25 connector. The Multi-Function LD Card is wired as a DCE (Data Communications Equipment) device. Therefore, it would
normally be connected to a DTE (Data Terminal Equipment) RS-232 device. You might need to run a special cable or use a special adapter if the serial port of the RS-232 device you want to attach is not the same type of connector as the one on your Card. Even if the
serial ports on the Card and the DTE are both RJ-45 connectors, you might still need to use a specially pinned cable. Call Black Box Technical Support with these issues, or if you want to attach a DCE device to the card.
The Modem-to-Modem Line Cables and Connectors:
The Multi-Function LD Card's line port is always the upper port on its interface module. It is a 6-pin RJ-11 connector, pinned for a standard telco-wiring environment, as shown below. The Multi-Function LD Card operates half-duplex over two wires (one twisted
pair) or full- or half-duplex over four wires (two twisted pairs). In all applications, the twisted-pair wire must be 26 AWG or thicker, unconditioned, dry, or metallic. Both shielded and unshielded cable yield favorable results.
NOTE:
The Multi-Function LD Card can only communicate in a closed data circuit with another Multi-Function LD Card. It will not work with dialup analog
circuits, such as those used with standard modems. For further information about acceptable wire grades, call Black Box Technical Support.
The modem-to-modem cable connection must be specially cross-pinned, as shown below. If your cabling includes punchdown blocks, you can easily do the cross-pinning at a punchdown block. If you will be running cable directly between two Multi-Function LD
Cards, you can get a custom cable from Black Box as a special quote, or you can use regular straight-through pinned cable and repin one of the RJ connectors (that is, rearrange the wiring connections between the terminal block and the actual contacts). You might
need special crimping tools or new connectors; call Black Box for these items, or for technical support if you have difficulty.
RJ-11 (Two-Wire)
Signal
Pin#
Pin#
Signal
XMT+
3
3
XMT+
XMT-
4
4
XMT-
RJ-11 (Four-Wire)
Signal
Pin#
Pin#
Signal
GND
1
6
GND
RCV-
2
4
XMT-
XMT+
3
5
RCV+
XMT-
4
2
RCV-
RCV+
5
3
XMT+
GND
6
1
GND
OPERATION AND DIAGNOSTICS:
Once you have configured each Multi-Function LD Card and connected the cables, you are ready to operated the units.
Status LED's:
The Multi-Function LD Card features 11 front-panel status LED's (shown on the first page) that indicate the condition of the modem and the communication link.
The TD and RD Indicators:
The TD and RD indicators (one red and one green LED for each signal) blink when data activity occurs: The red LED's indicate a low RS-232 logic level, while the green LED's indicate a high RS-232 logic level. Also, since RS-232 devices idle in a low
state, the red LED will be steadily lit if the connections are correct and the RS-232 device is in an idle state.
The RTS and CD Indicators
:
The RTS and CD indicators (again, one red and one green LED for each signal) function much like the TD and RD LED's: The red LED's light for a "low" signal, while the green LED's light for a "high" signal. The RTS LED's light for an incoming RTS signal
on the RS-232 side (DB25 Pin 4). The CD LED's light for an incoming signal on the line side and the resulting output signal on the RS-232 side (DB25 Pin 8).
RJ-11
1 2 3 4 5 6
