Lasair II Particle Counter Operations Manual Page F-1
Appendix F
PMS Multi-Drop Protocol (MiniLaz
Emulation)
This protocol is designed to be used on an RS-485 based system, with multiple
individually addressable instruments. All communications are polled with a sensor
address. The host program must take care of querying the unit for data.
RS-485 communications require an external RS-232 to RS-485 converter. The
converter must support automatic send data control. Older converters which require
CTS control (hardware flow control) will not work properly.
Tested RS-232/RS-485 converters
Both of these models have been tested with the Lasair II particle counter in MiniLaz
emulation mode connected to Facility Net.
NOTE:
A null modem is required to connect between these models
and the Lasair II particle counter.
• RS-232 to RS-485 converter with automatic send-data control and
opto-isolation: P/N 485OT9L
• RS-232 to RS-485 Converter with automatic send-data control and quick-
disconnect terminal block: P/N 485PTBR
Both of the preceding models are available from:
B & B Electronics
707 Dayton Rd.
P. O. Box 1040
Ottawa, IL 61350
Phone: (815) 433-5100
Web: http://www.bb-elec.com
Both models require external 12 VDC power @100 mA. One solution is the
120 VAC to 12 VDC supply P/N 485PS2.
To Next Page
Loading...
Need help?
General
