The Rs-232 Connector - Metro DataVac DPC 20 User Manual

is true independently of the measurement mode chosen for the SPC400 Aerosol (i. e.
measurements part by part or characteristic by characteristic ).
Important : Once all pressure measurements have been downloaded to the SPC400
Aerosol, leave the manometer connected until the message « end of sample »
appears on the screen. This is to allow memory reset of the DPC 20.
5. HOW TO USE THE SERIAL LINK (RS-232)
This interface enables release and transfer of measurements to a PC or an SPC400
Aerosol as well as loading of configuration parameters from a PC.
The protocol of communication of the manometer is as follows:
-1200 baud, 8 bits, no parity, 1 stop, no hand shake

5.1 The RS-232 connector

The connector is equipped with a Sub D 9 pin-plug.
Description of signals and assignment of pins.
Pin Signal
1
2 RX
3 TX
4 9V
5 Gnd
6 to 9
5.2 Commands
NOTE: In the following examples, '_' indicates a space character (ASCII code 32),
CrLf indicates the codes Cr (code 13) and Lf (code 10). Messages containing
« ****** » are error messages.
You will find below a presentation of each of the commands the manometer is able to
receive.
5.2.1 Transfer of the measurement made on part number n
Command: nCrLf
When receiving this command, the manometer will transfer the value of
measurement number n. n can assume any value between 0 and 20 expressed in
ASCII code on one or two bytes:
If n = 0, the transferred value is always the one displayed !
If sample size = 0, whichever measurement number is requested, the manometer will
always transfer the current measurement.
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Direction Description
Reserved (do not connect)
Input Reception of data
Output Transfer of data
Input Battery power supply
- Ground
Reserved (do not connect)
MANOMETER DPC 20
HOW TO USE THE SERIAL LINK