717/727 CONDUCTANCE MONITOR DATA SCHEME
Serial port settings are: 4800 Baud, 8 Data
Bits, No Parity, 1 Stop Bit
The data
communication scheme used is a polling
system in which the
PC sends a request to the 717/727 by sending as data
the channel
number of the 717/727 instrument. On single
channel systems, this
number is set to 16 binary (0001 0000, or hex
10). After the 717/727
reads
it's channel number on the serial port, it sends a six byte string.
The format is as follows:
Byte 1: This byte set to 1111 1111 (hex FF),
and
is used only as the
marker for the beginning of the byte string.
The software in the PC
tests for this byte before it accepts the following
five bytes as
valid.
Byte 2: This byte is used to send information
on sign, range, and
overange conditions. Only the three lower bits
are used, the other
bits are always 0,
except bit 7 which is always 1.
0100 0000
| | |----Sign, 1
= Negative
| |-----Range, 1 =
High Range
|------Overrange = 1
Byte 3 and 4: These bytes give the conductance
value, with byte 3
being the most significant.
Byte 5 and 6: Normally not used.
Note: The cable type required is an IBM AT
type Serial Cable.
(25 Pin
Straight Thru, or 9 Pin Female to 25 Pin Male)
Serial Port Settings
and Data Format Above information in text file.
Graphical
Interface Program (DOS) Standard Range Instruments
The following programs have been tested on DOS,
Windows (95,98, 2000, and XP),
and Linux using Dosbox.
Character-based
Interface
Program 100-200 Mho Instruments
Character-based
Interface
Program Standard Range Instruments
Character-based
Interface
Program High Sensitivity Instruments