User`s manual

3.2.4 Precautions for system configurations

The following describes the precautionary items when configuring the system to perform data communication with an

external device or call a pager receiver via public line, an office telephone system or digital line (ISDN) using the Q

series C24 modem function.

(1) Usable Q series C24 interface

(a) The modem function can be used for the RS-232 interface only.

(b) For the QJ71C24(N)-R2 and LJ71C24-R2, the modem function can only be used for

only one of the two RS-232 interfaces.

is not possible.

(2) Connectable modem/TA

(a) Only the modems/TA indicated in Page 83, Section 3.3.2 can be used for the Q series

C24 RS-232 interface using the modem function.

(3) Number of connectable modems/TA's

(a) Only one modem/TA can be connected to the Q series C24 RS-232 interface that

uses the modem function.

(4) Modem/TA connection cables

(a) The RS-232 cable supplied with the modem/TA or the designated modem/TA cable

can be used for connection between the Q series C24 and modem/TA.

(b) For the RS-232 interface of the Q series C24, a D-sub 9-pin connector (female) is

used. For the connection cable of the Q series C24 side, refer to the User's Manual

(Basic).

(5) Modem/TA installation

(a) Install the modem/TA according to the modem/TA manual. When installed in an area

in which a lot of noises exists, malfunctions may occur.

(b) In order to prevent the effects of noise and power surges, do not connect near or tie

the cable together with a main circuit line, high-voltage line or load line other than

for the programmable controller with the modem/TA connection cable.