Ohaus CKW WASHDOWN CHECKWEIGHING SCALES_INDICATOR CKW RS485_422 Serial Interface Option Kit Manual multi - Manual (Page 6)

CKW Serial Interface Option Kit EN-5
Jumpers (Cont.)
The jumpers are used as follows:
W1: Open = 4-wire operating mode. Shorted = 2-wire operating mode.
W2: Open = No Termination Load. Shorted = 120 Ohm Termination Load.
Note: When W2 is shorted, the termination resistance is placed between the Rx+
and RX- lines.
CAUTION: The use of multiple termination resistors may reduce the total number of
devices that can reliably operate on a single cable system.
Other Consideration
Avoid running RS485/422 system cables near other cables that may carry high
currents. High currents on nearby cables could induce noise voltages on the
RS485/422 cabling. If close contact is unavoidable, cross cables at right angles
to minimize interference. The use of high quality shielded cable will also minimize
undesired noise pickup.
On a typical long cable system, tap points or “T” connections should be kept to a
minimum length to reduce signal reflections.
Some RS485 systems may require additional bias resistors on the signal lines.
The CKW RS485/422 Option does not provide for these connections. If this type of
connection is required it will need to be provided by the main controlling device or
host system.
This section is similiar to the information
appearing in the CKW Instruction manual.
Figure 3 illustrates the structure of the CKW
Communication Menu.
The Communication menu is used to
configure communications parameters of
the serial port.
Menu Settings COM
Reset: No, Yes
Baud Rate: 300, 600, 1200, 2400,
4800, 9600,19200
Parity: None, Even, Odd
Data Length: 7, 8
Stop Bit:
1, 2 22 22
Handshake: None, XON/XOFF
Type:
RS232, RS485
Alt Command: Print, Tare, Zero
End
Figure 3. Communication Menu.
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