Installation 
EST3 Installation and Service Manual  5.53 
Connecting an external modem for use with the Remote 
Diagnostics Utility 
Using the Remote Diagnostics Utility requires that you connect 
an external modem to a CPU equipped with a 3-RS232 option 
card. 
Some applications may require that the modem be permanently 
mounted. The following is a suggested method for mounting a 
modem connected to the CPU. First you will need to obtain the 
following parts 
•  MFCA accessory enclosure 
•  SIGA-MP1 mounting plate 
•  2 cable ties long enough to go around the modem and 
through the slots on the SIGA-MP1 
To mount the modem: 
1.  Mount the MFCA enclosure back box at an acceptable 
location within reach of the panel. Refer to Figure 5-12. 
2.  Secure the modem to the SIGA-MP1 with the 2 cable ties. 
3.  Screw the SIGA-MP1 to the MFCA enclosure back box. 
4.  Connect all modem wiring. Refer to the technical 
documentation that came with the modem for wiring 
connections. 
  RS-232 wiring must maintain a 1/4-in minimum separation 
between nonpower-limited wiring. 
5.  Screw the MFCA cover to the back box. 
6.  Attach the modem RS-232 wires to the CPU serial port 
terminals. The serial port must be configured for Remote 
Diagnostics in the project database. See below. 
CPU
TB2
R
X
111
T
X
R
T
S
2122
C
X
O
M
R
R
T
X
T
S
2
C
O
M
DB-25 male connector (rear view)
to modem RS-232 connector
Modem serial cable