Remote Processing RPC-330 - Manual (Page 10)

SETUP AND OPERATION SECTION 2
Page 2-4 RPC-330
WHERE TO GO FROM HERE
If you want to do this: Turn to
Section
Save a program 3
Run a program at power up or
reset (autorun) 3
Know m ore abo ut serial por ts 4
Install a differ ent RAM mem ory 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 c urre nt outputs 6
Connect an external opto rack 6
Calendar/ clock option 7
Use displays 8
Connect a keypad 9
Measure voltages 10
Interr upts 12
Multi-mode counter 13
Output a voltage 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 the
end of this section. The 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 pow er ter minal, the RPC -330 will r eset.
Power is 5 ±0.25 volts. Make sure it is a clean 5
volt source . If it dips in term ittently 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 per manen t reset. Check U7, pin
8. If it is hig h (about 5 volts), then the car d is in
reset. T his line should be low (about 0 volts).
2. Check the COM 0 port (J3). Rem ove the connector
from COM 0. R efer to the outline dra wing ear lier in
this section. Connect an oscilloscope (preferred) or
a voltmete r to pin 3 (T xd) and gr ound. Pin 3 should
be -6 volts or more negative. (Pin 1 is designated
by the
v symbol on the connecto r. 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 A C, you
should see a mom entary rea ding above 2 volts.
3. Install the 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 th e output.
4. Check the serial pa ram eters on y our P C or termin al.
They should be set to:
9600 baud, no parity, 8 data bits, 1 stop
5. If you are receiving a sign on me ssage but not ab le
to enter characters, check U8, pin 4 for at least -6
v o lt s. W h e n i t i s n e ar 0 vo lt s, t h e t er m i na l o r P C ' s
Tx line is not connected. When you pr ess a
character on the terminal or P C, you should see the
voltage go positive.
If all of this fails, call technical support listed in section
1.