SECTION 4D - HAYES COMPATIBLE MODEM INTERFACE
INTRODUCTION
The Model 16, with software version 1.20 or later, is equipped with a
software interface which allows it to control an external Hayes compatible
modem so that connection can be made to the Model 16 over telephone lines
using standard communications equipment, usually a PC running a terminal
emulation program. The Model 16 operates in an answer only mode; thus this
section does not include any reference to call origination. The Model 16 is
designed to work with modems that are fully Hayes compatible, it uses the
"AT" command/response codes. It provides programming of the modem
initialization string and the modem hangup string for installations
requiring settings that deviate from the factory defaults. The programming
for these items is very similar to some of the more popular communications
software packages.
PROGRAMMING
To use a Model 16 with a Hayes compatible modem, the Model 16 must first be
programmed for modem operation. To do this, connect a dumb terminal or a PC
running a terminal emulation program to the Model 16. The baud rate and
parity should be set the same as the Model 16 (9600 baud, no parity is the
factory default). The other communications parameters should be 1 start
bit, 1 stop bit, full duplex.
The programming mode is accessed in the usual manner by logging on with a
<CR> (carriage return). Then following "ID= " from the Model 16, enter a P,
and then enter the program mode Access code. Once logged on, enter S for
system programming, then press "C" for the communications menu. The Model
16 will ask if a Hayes compatible modem is installed, answer "Y" for yes.
Next, the Model 16 will ask if you want to set the modem initialization
string. The factory default initialization and hangup strings should be
adequate for most installations and do not normally need to be changed. If
you do need to change either of these, then simply answer yes in response
to the appropriate menu item and answer as needed to the prompting from the
Model 16. Any other parameters that do not need to be changed can be
skipped by pressing <CR> (carriage return) in response to the menu item.
The serial port baud rate should be set to the highest the modem is capable
of communicating at, up to 9600 baud.
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C A U T I O N
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You should not set the serial port baud rate any higher than the modem is
capable of communicating at. If the modem is capable of rates higher than
9600, then you must set the modem so that it does not attempt a higher
rate.
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4D-1
