Intermec EasyCoder 501 – Service Manual Ed. 7
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Chapter 21 RS-422/485 Interface Board
21.2 Straps
Communication Port "uart2:" (RS-422/485)
P-3 Selects 2- or 4-wire communication (see text on board).
P-7 Selects address for the printer (only used in RS-485 con-
nection with "prot. addr. enable") according to the table
later in this chapter.
P-8, P-9 Voltage reference straps.
RS 422: P-8 and P-9 should be strapped on both units.
RS 485: P-8 and P-9 should be strapped on "master" unit.
Usually, the host computer is master.
P-10 100 terminating resistor. Should be strapped on the fi rst
and last units, regardless of RS-422 or RS-485.
P-11 100 terminating resistor. Should be strapped on both
units in an RS-422 line.
Communication Port "uart3:" (RS-232)
P-6 Co5V to pin 16 on "uart3:". Max 200 mA.
Caution! Be careful not to enable the ex5V unin-
tentionally, which may cause harm to the terminal, com-
puter, or other device connected to this port!
P6
P3
P11
S1
S2
S3
S4
S5
P10
P9
P8
MASTER
END
P7
2-WIRE
4-WIRE
5V-EXT
"uart3:"
P-9
P-8
"uart2:"
P-10
P-11
P-7
P-3
P-6