SETUP AND OPERATION SECTION 2
Page 2-4 RPC-320
WHERE TO GO FROM HERE
If you want to do this: Turn to
Chapter
Save a program 3
Run a program at power up or
reset (autorun) 3
Know more about serial por ts 4
Install a different RAM memory chip 5
Using RAM to save variables 5
Run an assembly language program 5
Configure digital I/O lines 6
Detect on/off switch status 6
Use high current outputs 6
Connect an external opto rack 6
Calendar/clock option 7
Connect Displays 8
Use a keypad 9
Measure voltages 10
Using inter rupts 12
Multi-mode counter 13
Use low power operation 14
Refer to the table of contents for a more detailed listing.
TROUBLESHOOTING
You would probably turn to this section because you
could not get the sign on message. If you are getting a
sign on message but can't enter characters, then read
section 5 below. T he following are troubleshooting hints
when you can' t get anything.
1. Check the power source. If it is below 4.65 volts at
the input power terminal, the RPC-320 will reset.
Power is 5 ±0.25 volts. Make sure it is a clean 5
volt source. If it dips intermittently to 4.65 volts
(due to switching noise or ripple), the card will reset
for about 100 ms. If the noise is frequent enough,
the card will be in permanent reset. Check U7, pin
8. If it is high (about 5 volts), then the card is in
reset. This line should be low (about 0 volts).
2. Check the COM 0 port (J3). Remove the connector
from COM 0. Refer to the outline drawing earlier in
this chapter. Connect an oscilloscope (preferred) or
a voltmeter to pin 3 (Txd) and ground. Pin 3 should
be -6 volts or more negative. (Pin 1 is designated
by the v symbol on the connector. Pin 3 is next to
it, nearer the key opening.) If you have -6 volts or
more, press the reset switch. If you have a scope
attached, you should see a burst of activity. With a
volt meter, you should see a change in voltage.
Using a Fluke 8060A set to measure AC, you
should see a momentary reading above 2 volts.
3. Install the serial cable and make sure the voltages
and output activity are still there. Output is from
pin 3 on the VTC-9F. If not, check to make sure
something is not shorting the output.
4. Check the serial parameters on your PC or terminal.
They should be set to:
9600 baud, no parity, 8 data bits, 1 stop
5. If you are receiving a sign on message but not able
to enter characters, check U8, pin 4 for at least -6
volts. When it is near 0 volts, the terminal or PC's
Tx line is not connected. When you press a
character on the terminal or PC, you should see the
voltage go positive. Check the serial cable.
Transmitted signals from the PC or terminal are
from pin 5 on the 10 pin IDC connector.
If all of this fails, call technical support listed in chapter
1.
