COMPUTER AIDED DIAGNOSTICS
Computer Monitor Set-up
Summary: With its serial port connected to the TCIV CPU, directly or through a modem, a computer
provides a powerful system analysis and troubleshooting tool. A dumb computer terminal or
one that can act dumb is required for these procedures. (See
Drawing KM0873
for modem
connections.)
Caution:
The TCIV does not supply the negative voltage required by RS232 standards; however, most
serial ports will still work with the TCN CPU. Ensure compatibility before procuring a system
for performing these procedures.
Step 1. Build a cable to go between the computer serial port and the TCIV 4 pin connector on the
CPU
Note:
This cable is similar to the one required for connecting a modem to the TCIV. See
Drawing KM0873; if using a laptop, use 9 pin connector pins 3, 2, and 5 instead of RS232 25
pin connector
pins
2, 3,
and 7, respectively.
Step 2. Install a communication program in the computer and set it up in accordance with the
following checklist.
Baud rate =
Jumper setting on TCIV CPU.
Com
Port = Serial Port
(COMl,
COM2,
etc.).
8
bit, no parity.
Full Duplex (Input
characters are displayed when returned from the TCIV.)
Step 3. Test the program by connecting the serial port cable connector
Out
jack to its In jack, start
the program, and type some characters. If it is operational, they will appear on the screen.
Remove the jack and type some characters; they should not appear on the screen if
operating
in full duplex mode.
(Out
and In refer to the direction of signal flow and are always con-
ncctcd out to in; otherwise, the two outputs wilt compete for control of the voltage on the
terminal and the two inputs wilt wait for drive signals.)
Step 4. Install the modem or serial port connector onto the CPU, ensuring
Out goes
to In and vice
versa .
step 5. Press the Reset button on the CPU and verify that T5 appears on the terminal screen. This
indicates the CPU self test of memory, clock, and UART was successful. If it is not received,
check and correct any problem with the following:
5 volts power at the CPU
Baud rate and other settings as described in Step 2.
Serial port connection between the TCIV and the computer or modem.
