Intermec EasyCoder 501 Service Manual page 168

21.2 Straps, cont.
RS-422 POINT-TO-POINT
(printer to printer)
+ - + -
1 7 15 17 19 21
PRINTER P-2
P-11 P-10
100 ohm 100 ohm
P-9
+VEE
P-8 and P-9 strapped on both units.
P-10 and P-11 strapped on both units.
Connection P-2 pin 7 to Chassis GND
(for example P-2 pin 1) on one unit only.
RS-485 MULTIDROP LOOP
(w. printer as master unit)
+ -
1 7 19 21
PRINTER (master) P-2
P-10
100 ohm
P-9 P-8
+VEE GNDE
P-8 and P-9 strapped on master unit.
P-10 strapped on first unit.
Connection P-2 pin 7 to Chassis GND
(for example P-2 pin 1) on one unit only.
Intermec EasyCoder 501 – Service Manual Ed. 7
The illustrations below show how the voltage reference straps
and terminating resistor straps should be fi tted on the RS-422/485
interface boards. When a computer is connected to the line or loop,
the same principles apply. Refer to the computer manuals for infor-
mation on how to appoint the computer "master" and how to set
the termination.
Screened twisted 4-line cable (approx. 50 pf/m)
P-8
GNDE
Screened twisted 2-line cable (approx. 50 pf/m)
+ -
7
19 21
PRINTER P-2
P-10
100 ohm
P-9
+VEE
No straps
Chapter 21 RS-422/485 Interface Board
+ -
7
19 21
PRINTER
100 ohm
P-8 P-9
GNDE +VEE
No straps
+ - +
7
15 17 19
PRINTER
P-11
100 ohm 100 ohm
P-9
+VEE
P-8 and P-9 strapped on both units.
P-10 and P-11 strapped on both units.
+
7
19
P-2 PRINTER
P-10
P-8
GNDE +VEE
P-10 strapped on last unit.
-
21
P-2
P-10
P-8
GNDE
-
21
P-2
P-10
100 ohm
P-9 P-8
GNDE
167