Westermo MA-66 - Manual (Page 6)

12 6066-2001
Hints
If any problems occur upon set-up of the MA-66, the following notes may be helpful.
1. Power up the MA-66 and check that
the PWR LED is lit.
2. Check the cable between your RS-232
interface and the RS-232 connection on
the MA-66. The RS-232 interface on the
MA-66 is configured as DCE (Data
Communication Equipment). Most prin-
ters, PCs and terminals are set as DTE
(Data Terminal Equipment). See the
3 suggestions of cable configurations on
pages 13.
How to check whether the equipment is
DTE or DCE:
•
Power up the unknown equipment and
ensure that nothing is plugged into the
RS-232 interface. Using a multi-meter,
first measure the voltage on pin 2 of the
connector (male or female) with refe-
rence to ground on pin 7 (25 pole
connector) or on pin 5 (9 pole connec-
tor, PC standard). Then measure the
voltage on pin 3 in the same way. The
pin with the most negative voltage will
be the output pin and will identify the
device as DCE or DTE.
9 pole connector,PC standard
•
If the most negative voltage is on pin 3:
the device is DTE.
• If the most negative voltage is on pin 2:
the device is DCE.
25 pole connector, PC standard
•
If the most negative voltage is on pin 2:
the device is DTE.
• If the most negative voltage is on pin 3:
the device is DCE.
3. The RS-232 cable is correct but it still
does not work. The LEDs may be helpful.
• PWR: The unit has power
• RD: Data received from fibre
interface
• TD: Data received from RS-232
interface
• RTS: RTS from RS-232 side
• CTS: RTS from the line side
4. Test each individual modem. All switches
in OFF state. Make sure that the mains-
power socket is disconnected when the
modem lid is off.
A. Equipment required: a terminal or a PC
with terminal program, an RS-232 cable
according to point 2, and a fibre cable.
B. Connect a cable between the modem
and terminal, or PC with a terminal
program. Connect the fibre cable bet-
ween RX and TX.
C. Press any key on the keyboard. During
keystrokes, the TD and RD LED’s
should flash on the modem, simultane-
ously, the characters will be echoed on
the monitor.
D. If the fibre cable is removed from one
port only, the TD LED will flash when
a key is pressed, but no characters will
appear on the screen.
Repeat the same test with the second
modem.
5. Testing the modems together.
A. Leave the last tested modem in place,
connected to the terminal or the PC
(modem A).
B. Connect two fibre cables between the
modems RX (modem A) – TX (modem
B) and vice versa.
C. Connect pins 2 and 3 of the RS-232
interface on modem B (top screw ter-
minal 7, 8).
D. Press any key on the keyboard. During
keystrokes, the TD and RD LED’s
should flash on the modem, simultane-
ously, the characters will be echoed on
the monitor.