Ericsson EDACS LBI-39077 - Manual (Page 39)

DATA LINK TO GTI UNITS LBI-39077
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6. After selecting an operation from the Comm group in the Main Menu screen and selecting the system, you will need
to wait for the answer prompt, then press the Enter key to tell the GTI Configurator to send the overdial digits to
connect the internal modem and begin sending the originate tone.
REMOTE DATA LINK WITH EXTERNAL GTI MODEM
If the distance between the GTI unit and GTI Configurator is longer than 50 feet, modems will be needed on each end of a
telephone circuit between them. If the 1200 bps modem built into the GTI unit isn’t fast enough for your application, or you
don’t want to reduce the number of lines available for interconnect calls while the GTI Configurator is communicating with
the GTI unit in the system, you can use an external modem connected to the RS-232 port of the GTI unit. This will require the
following additional equipment:
•
External modem at the GTI unit location and a cable to connect it to the RS-232 port on the back of a GTI unit
•
Matching modem at the GTI Configurator location (internal or external - cable required if external)
•
Available telephone line or other communication circuit and a cable to connect from it to the modem (at both
locations)
Normal Setup
To set up a remote RS-232 link with an external GTI modem, use the following procedure:
GTI Unit GTI Configurator
Serial COM Port
RS-232 Port
Modem
Telephone
Hayes
(or equiv.)
Exchange
LINE
or
TELCO
Serial
COM Port
Modem
Hayes
(or equiv.)
LINE
or
TELCO
Serial
COM Port 9-Pin (F)
Figure 30 - Communication Setup Using External Modem
1. Connect the cables and modems between the GTI Configurator and the GTI unit as shown in Figure 30. The modem
at the GTI Configurator end is shown separate from the GTI Configurator, but could be built into the GTI
Configurator. It is preferable to use identical modems at both ends to minimize compatability problems.
•
Use a standard modem cable between the GTI Configurator (DTE equipment) and the modem (DCE
equipment). The standard modem cable connects each pin at one end to the same pin at the other end.
•
Use a null modem cable between the GTI unit (DCE equipment) and the modem (DCE equipment). The null
modem cable connects each pin at one end to the same pin at the other end, except for pins 2 and 3 which are
crossed. Be sure to use a cable containing the DTR wire (pin 4 in DB-9 connector). The DTR line will be used,
instead of the escape code, to tell the modem when to hang up.
•
Connect the lines between the telephone exchange(s) and each modem to the connector on the modem labeled
LINE or TELCO (not the connector labeled PHONE or LOCAL). Do not bypass the telephone exchange by
connecting directly from modem to modem. The modems are designed to interface with a telephone exchange,
not with each other.
•
Be sure that each modem is plugged in, but wait to turn them on until after they have been configured.
2. Configure the external modem at the GTI unit end as follows (see the modem manufacturer’s manual for directions):
•
Set the modem for normal DTR operation. This line will be used to tell the modem when to hang up.
•
Set the modem to send verbal result codes. The GTI unit does not recognize numeric result codes.