26
6.10 Using the RS-232 Port
The RS-232 port is used to monitor dryer operation from
a host computer.
RS-232 connections are made at the 3-pin connector
labeled J3 and located at the upper left-hand corner of
the control board.
Interface to a PC requires a (1 to 1) DB-9 cable.
Cable Pin Out:
- Data transmitted on pin 2
- Data received on pin 3
- Ground is pin 5
- Pins 7 and 8 are jumpered at the dryer
Operation:
1. Fixed baud rate of 9600
2. Asynchronous format is 8 bit, no parity, 1 stop bit
(“8,N,1”)
3. No check sum or error correction values are pro-
vided. If required, request status string two (or more)
times and compare for agreement.
4. Request data by sending ASCII ? character (3FH).
Response may take up to two seconds as certain
processing functions may require completion before
the serial port is acknowledged.
5. The dryer responds with line feed (0AH), carriage
return (0DH), and a character string as follows:
STX Start of text character 0x02
109
Three character ASCII device identifier
,
comma character
x
ASCII representation of the cycle type
,
xx
ASCII representation of the cycle step
,
xxxxx ASCII representation of the current cycle time in
seconds
,
xxx
ASCII representation of the inlet temperature (°F)
,
xxx
ASCII representation of the heater temperature
(°F)
,
xxx
ASCII representation of the left bed temperature
(°F)
,
xxx
ASCII representation of the right bed temperature
(°F)
,
xxx
ASCII representation of the humidity sensor tem-
perature (°F)
,
xxx
ASCII representation of the humidity sensor rela-
tive humidity (%)
,
xxxx ASCII representation of the dew point reading (°F)
,
xxxx
ASCII representation of the filter time to service
(hours)
,
xxxx ASCII representation of the desiccant time to
service (hours)
,
xxxx ASCII representation of the valve time to service
(hours)
,
x
ASCII representation of programming jumpers
,
1 or 0
Is the unit alarmed? 1 = alarm
,
1 or 0
Is service required? 1 = service
,
xx
ASCII representation of the energy savings (%)
,
x
Reserved for future use, always 1 for now
,
ETX end of text character OxO3
CR
carriage return
LF
line feed
JUMPERS:
The programming jumpers are as follows (0=off, 1=on):
JP Bit
1 0
off = externally heated
on = blower dryer
2 1
on = energy management sensor installed
3 2
on = dew point sensor installed
4 3
on = no cooling (blower purge only)
5 4
on = tower pressure switches installed
6 5
on = not used (fast cycle for development, V3.5
and prior)
7 6
on = to download language text (factory use)
8 7
on = to enable factory set-up screens
Determining jumper positions:
Each jumper 8 bits weighted by position
JP
Value
8
128
7 64
6 32
5 16
4
8
3
4
2
2
1
1
