COMMS # 25

	FECO:	COMMS # 25
	MODIFICATION No:	N/A
	PRODUCT:	GANDALF QX4232 MODEM
	SUB-ASSEMBLY	N/A
	ESTIMATED MAN HOURS	N/A
	CLASS OF CHANGE:	INFORMATIONAL
	REASON FOR CHANGE:	TO RELEASE THE SYNCHRONOUS SET UPS FOR THE 4232

1.This Feco details the synchronous set up procedure for the 4232 modem as used as part of an extended
        communications network. The 4232 can be used to replace the 3242 as shown in FECO COMMS # 16, and
        used in conjunction with a kmux or 2120 as detailed in FECO'S COMMS 15 and 22.

        A typical network is shown below.

        This feco is complementary to FECO COMMS # 18/4 which details the 4232 standard asynchronous set ups.

        (tech serv ref 3/1/1)

        Change

2.full esd precautions must be applied at all times.

3.synchronous set up procedure.

3.1ensure the power is disconnected from the modem.

3.2remove the front faceplate by inserting a small screwdriver in the lower middle notch of the faceplate and pop
        out the faceplate. This allows access to the front set of dip switches.

3.3remove the single screw from underneath, located at the rear centre, between the feet. It may be located
        underneath a label.

        Note: there are two small holes 1/8 inch in diameter approx two inches from each side, near the screw;
        these do nothing.

3.4raise the top cover at the rear about 2 inches, springing it off the retaining clips, slide the top cover towards
        the front to release the hooks, and lift off.

3.5the pcb just sits in the base. It can now be lifted out if required. Access is now available to the internal dip
        switch.

3.6note: the modem must be set to an asynchronous mode for the initial part of the set ups, then finally set to
        the synchronous mode.

3.7initial dip switch settings.

        Set the switches as listed below.

        Rear switch (sw6) all up

        Front switch 2 3 down the rest up

        Interior switch (sw5)

        1 2 3 4 5 6 7 8

        On off off on on off on on

        Note: the above is the final setting for the interior switch.

3.8set the jumpers as shown in the diagram.

3.9reassemble the modem in its cover, but do not replace the front faceplate at this time.

3.10connect a vdu to the modem data connector.

3.11connect power to the modem and allow it to run through its start up sequence.

        Diagram

        Rear

        To

        Dial to

        Up leased reset

        Line line vol rear switches rs 232

        19vac

        87654321

        Pot

        Jp9::| j7

        Jp8::| . Jp10

        |:| jp11

        Sw5

        |::jp1 1

        2

        3

        4

        5

        .jp4 6

        7

        8

        Daughter board

        Sw2 sw3

        1234567891

        0 l e d s

        G r r rg r r r

        Front

3.12enter at and ensure the modem responds ok.

3.13enter at&f&w to default.

3.14for modem nearest host (called host modem)

        Enter at\d0:n0s10=0s25=30&x1&w*wo

        For modem furthest from host (called remote modem)

        Enter at\d0:n0s10=0s25=30&x2&w*w0

3.15enter at\s to display and check new settings.

3.16remove the power from the modem and disconnect the vdu.

3.17final dip switch settings.

        Front

        1 2 3 4 5 6 7 8 9 10

        Up down up up up up up down down up

        Rear

        1 2 3 4 5 6 7 8

        Up down up up down down down up

3.18replace the front faceplate.

3.19ensure the front panel switches are:

        Td - out

        O/a in on host modem

        Out on remote modem

3.20the modem is now set up

3.21connect modem to network and power up.

4.setup parameters

        &c1cd follows carrierrear sw 6-8

        &d2respond to dtrfront sw1

        \d0 dsr & cts always onrear sw 6-8

        %h0v24 v54 test modes offrear sw3

        %l1speed matching onrear sw8

        &l4enable 4 wire leased linefront sw 6-8

        :nodisables leased line dial

        Back up mode

        &r1cts ignores rts in synchronousrear sw 6-8

        Mode

        S10delay for hang up after carrier

        Loss

        S25delay to dtr and asynchronous /

        Synchronous time delay

        &x1dte must supply the transmit clock on pin 24 for the modem to pass data. The modem provides the
        receive clock on pin 17 of the serial port.

        &x2slave transmit clock. The modem derives the transmit clock from the receiver of the local modem and
        provices it on pin 15, and provides the receive clock on pin 17.

        &wstore current configuration.

        *wstore complete configuration.

        Line speed 9600rear sw 1-2

5.cabling

        The cable connecting the mmux and the 4232, is a standard cable; cable type k

        Ie, pins 1-25 straight through.

        However, the cable connecting the 2120 and the 4232 is a synchronous crossover. The spec is
        listed below:

6.ensure the 2120 channel connected to the 4232 has the channel clocking set to x-dce.

7.Testing

        Test for function.

8.recording action

        No specific recording action.

        Normal documentation is to be completed i.a.w qpgen-010

Return to Index