Laurel Electronics Laureate Digital Panel Meter for Load Cell & Microvolt Input - Manual (Page 3)

LAUREL ELECTRONICS INC., 3183-G Airway Ave., Costa Mesa, CA 92626, USA • Tel 714-434-6131 • www.laurels.com 3
Serial Data I/O (optional)
Board selections
Protocols
Data rates
Digital addresses
Isolation Ethernet, Ethernet-to-RS485 server, USB, USB-to-RS485 server, RS485
(dual RJ11), RS485 Modbus (dual RJ45), RS232.
Modbus RTU, Modbus ASCII, Laurel ASCII protocol
300 to 19200 baud
247 (Modbus), 31 (Laurel ASCII),
250V rms working, 2.3 kV rms per 1 min test
Signal Connections
Environmental
Operating temperature
Storage temperature
Relative humidity
Protection 0°C to 60°C
-40°C to 85°C
95% at 40°C, non-condensing
NEMA-4X (IP-65) when panel mounted
Load Cell Meter Connections
In 4-wire connection, the excitation and sense lines
are tied together. The meter can make ratiometric
corrections for supply voltage variations, but not
compensate for variations in lead resistance. This
connection is often used with short cable runs.
In 6-wire connection, the sense lines are separate
from the excitation lines, thereby eliminating effects
due to variations in lead resistance. This allows long
cable runs in outdoor environments with temperature
extremes.
For large scales, up to four 350 ohm load cells can
be powered by a single Laureate, whose excitation
output is rated 120 mA at 10 V. The excitation and
sense points of the four bridges are connected in
parallel through a summing box.