Symbol Technologies MK1000 - Manual (Page 36)

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MK1000 MicroKiosk Product Reference Guide
Wired RS-485 Setup
The MK1000 can communicate with a host via a wired RS-485 Serial connection while
receiving power via a power supply plugged into an AC outlet.
For MK1000 devices installed where pre-existing PCK 9100 wiring exists, an RS-485 pin-
out converter can be used. This pin-out converter maps the PCK 9100 signals into the
required MK1000 pin-out and attaches to the existing PCK 9100 wiring, and then into the
MK1000.
RS-485 is a two-wire differential signal: RS-485 signal and RS-485 inverted signal. See
Figure 2-2 on page 2-8 for an illustration of the two-wire differential signal.
When installing an RS-485 configuration, ensure each MK1000 is connected directly to the
RS-485 bus (see
Figure 2-1 ).
Figure 2-1. Connector Block
The cable required for an RS-485 installation should meet or exceed the following
specifications:
• 1 twisted pair 26 AWG (7/34) tinned copper
• twisted pair foil wrapped - 100% coverage
• nominal impedance 120 ohms
• capacitance between twisted pair 10-25 pf per foot
• capacitance between conductors & shield 20-35 pf per foot
• DC resistance of each conductor 45 ohms per 1000 feet
• DC resistance of shield 10 ohms per 1000 feet.
If your host does not support RS-485 and you wish to use RS-485 as your communication
interface, an RS-232 to RS-485 conversion box is required. The conversion box must be
sourced locally and is not available from Symbol Technologies.
Wire nuts or connector
block may be used
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