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Communicating with the Intellect 69 via
Modem and Telephone Lines
Requirements
- Hayes compatible modem connected to Intellect 69
- RS232 cable to attach the modem to Intellect 69
- Modem and communications software for your PC
General
The Intellect 69 RS232 interface is a simple 3 wire communication system,
pins 2 and 3 carry data and pin 7 is the signal ground. Modems usually
require some additional hardware handshaking signals therefore jumpers
may have to be added to some of the modem inputs in order to make it fully
compatible with the Intellect 69.
The communications protocol used is: 8 data bits, 1 stop bit, no parity,
baud rates supported by the Intellect 69 are 300, 1200, 2400, 9600
Cable Connections Between the Modem and the Intellect 69
| Modem side 25 pin connector |
|
Intellect 69 side 25 pin connector |
| TD (pin 3) |
connect to |
RD (pin 2) |
| RD (pin 2) |
connect to |
TD (pin 3) |
| GND (pin 7) |
connect to |
GND (pin 7) |
| RTS (pin 4)- |
-| |
|
| CTS (pin 5)- |
-| jumper together |
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Modem Configuration
The modem must be configured in the following manner in order to work
with the Intellect 69.
- Disable data compression if present
- The modem must ignore the Data Terminal Ready signal (DTR)
- The Data Carrier Detect signal (DCD) must be set by the modem when
the remote carrier is detected
- Auto Answer must be enabled
- The modem must be in the Answer mode
- Result codes must not be sent
The above setup can be achieved either through the optional switch settings
on the modem or by setting up an AT command string. Refer to your Modem
Manufacturer's manual for details.
As a guide, the following AT commands should configure the modem in
the required manner.
- AT&D0
- AT&C1
- ATS0=1
- ATA
- ATQ1
The modem should be able to save these settings in the event of Power
loss. If this is not the case then the modem will have to be reconfigured
after every power outage. In order to save the settings use the &W0
command. Note that some modems do not require the ATQ1 setting.
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