Emerson Process Management ControlWave EFM 3808 - Manual (Page 77)

CI-ControlWave EFM Installation & Operation / 2-25
Modems are supplied in kit form with all the hardware required for user installation onto
an Expansion Communications Module. Figure 2-14 shows the modem mounted on the
Expansion Comm. Module.
Modems are user installed onto the ECOM Module (see Figure 2-14) and their associated
Ports are setup during installation in the Ports Page of the Flash Configuration Utility. The
Flash Configuration Utility is accessed via NetView or LocalView. A Terminal Emulation
program such as HyperTerminal is used to profile the modem via AT commands. Users
typically use AT commands only when checking the modem’s active or stored profile or
when reconfiguring a modem, e.g., to turn auto answer on or off, etc.
MultiTech Modems are pre-configured using the following 7 steps prior to being shipped.
• Enable modem setup by setting ECOM Board jumper JP2 to 2-3.
• Connect via HyperTerminal (Parameters = 9600, 8, N, 1, None) to ECOM port C1 using
the null modem cable (see Figure 2-12A or 2-13).
• Send Factory Default = AT&F0
• Disable Flow Control = AT&K0
• Set Baud using AT Command: AT$SB9600, or whatever baud rate you require.
• Write to Memory. = AT&W
• Disable setup mode. Park JP2 (no connection)
Note:
The modem can be reconfigured via AT commands using a terminal program
(such as HyperTerminal). Connect Pins 2 and 3 of ECOM Bd. Jumper Post JP2 via
a Suitcase Jumper. Connect the modem (via ECOM1 port COM4 or ECOM2 port
COM8) to the PC via a null modem cable (see Figure 2-12A).
Publicly Switched Telephone Network (PSTN) Hookup
A PSTN using a master and three remote Process Automation Controllers (each equipped
with a PSTN modem) is shown in Figure 2-15. A connection to the PSTN is made using a
cable having standard telephone connectors at each end. One end of the cable plugs into the
ECOM’s RJ11 connector jack while the other end plugs into a telephone company RJ11 wall
jack. The telephone company provides the necessary subscriber loops at its central system
along with the phone numbers for each destination.
Warning
Only one modem should be connected to each drop. If an attempt is made to parallel two or
more modems across a single drop, an impedance mismatch will occur and the quality of the
signal will be adversely affected. Modems will not provide reliable communications under
these conditions.
An application consisting of a single master and a single remote requires only one of the
remote connections shown in Figure 2-15.
The 56K PSTN Modem is FCC-approved for use with public telephone lines. Before placing
a modem in operation, the following items should be checked to insure that all FCC
requirements are met:
• Connections to party line service is subject to state tariffs.
• Connection to telephone company provided coin service (central office implemented
systems) is prohibited.
• The equipment compliance information is summarized as follows: