Ground Connections - OHAUS CKW Serie Instrucciones De Instalación Y Operación

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Ground Connections

A signal ground connection is recommended but not always required. The use of
a signal ground connection will help improve system reliability and noise
immunity. Systems without a signal ground can tolerate common mode voltage
differences of –7V to +12V. To reduce high common mode voltages, larger multi-
point systems may require the use of a signal ground wire with series resistors
inserted between each connection. The resistors reduce the currents that could
flow in systems with high common mode voltage differences. Resistor values of
100 ohms are typical.
Use of RS485 Addresses
The Industry Standard EIA-485 allows for driving up to 32 devices on a single
cable. The CKW RS485/422 interface option will allow up to 100 unique
addresses to be configured. The actual number of devices able to operate reliably
on a single cable will be dependent on the Master device's drive capability, the
cable quality, the data speed, and the cable length.
The use of scale addresses above the actual number of network connections
would allow for simplified swapping of scales on an existing network. Scales
could be swapped with no risk of repeated addresses on a network. Multiple
network systems could also be created with unique scale addresses to give
absolute scale identification.
The address may be disabled to allow compatibility with RS422 point-to-point or
receive only multi-drop systems.
CKW RS485/422 and RS232 Interfaces
When the CKW RS485/422 option is setup, the original RS232 output cannot be
used. This is because part of the original RS232 system is also used to support
the RS485/422 interface. Cable connections to both serial interfaces can remain in
place, but only one serial interface may be used at a time. Before use, the
required interface must be setup in the COM menu.
INSTALLATION
CAUTION: ELECTRICAL SHOCK HAZARD. REMOVE ALL POWER
CONNECTIONS TO THE INDICATOR BEFORE SERVICING OR MAKING
INTERNAL CONNECTIONS. THE HOUSING SHOULD ONLY BE
OPENED BY AUTHORIZED AND QUALIFIED PERSONNEL, SUCH AS
AN ELECTRICAL TECHNICIAN.
CKW Serial Interface Option Kit