User Manual SERVOPRO PLASMA Trace N
2
Analyzer
APPENDIX 4
71
Introduction
With this option installed, this analyzer retransmits the operating parameters and process values to a
remote computer through a serial link. The computer is connected to the analyzer by the mean of a
DB-9 RS-232C (Null-modem) cable. The computer must have appropriate software to read the data
transmitted by the analyzer. Any commercial software can be used to receive the data.
1. Description
1.1. Hardware
The RS-232 port on the analyzer is driven by an opto-isolator/convertor.
It is necessary to isolate the analyzer C.P.U. board and its power supply from spurious
interferences and transients otherwise these sources of interference could interact with the
analyzer and could even damage sensitive parts.
Another reason to provide isolation is to break any ground loop between the remote
computer and the analyzer C.P.U. board. Such ground loops could cause interference and
noise to the highly sensitive analogic electronic circuits of the analyzer.
The DB-9 serial connector mounted on the analyzer rear panel is a special one.
All precautions are taken to give a reliable serial transmission, even if the opto
isolator/converter system provides a barrier against noise, transient and ground loop, it
cannot support high voltage differences between two different floating systems. For this
reason, the remote computer and the analyzer must be properly grounded (ground at same
potential).
The standard RS-232C specifications stipulate a maximum distance of 15 meters between
two systems. But, if you are using good communications cable (good shielding and low
capacitance) longer distances may work successfully.
If you want to use a remote computer located far away from the analyzer (up to 1200 meters),
a RS-422 converter should be used to drive the communication lines.
A RS-232C null modem DB-9 cable is supplied with the analyzer. This allows direct
connection to a personal computer serial port.
The communication parameters of the analyzer are:
RS-232C SERIAL COMMUNICATION OPTION
To Next Page
Loading...
Need help?
General
