Symbol MK2200 MicroKiosk, Руководство по продукции

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Installation 2 - 11
Wired RS-485 Setup
The MK2200 can communicate with a host using a wired RS-485 serial connection, typically using the MK2200
Symbol AC power supply. When installing MK2200s where PCK 9100, PCK 9140, or MK1000 wiring exists,
connect that wiring directly to the MK2200.
RS-485 is a two-wire multidrop network: RS-485 signal and RS-485 inverted signal. See Figure 2-9 on page
2-13 for an illustration of a two-wire network.
Ensure each MK2200 is connected directly to the RS-485 bus with correct polarity (see Figure 2-8 ).
Figure 2-8
Connector Block
In an RS-485 installation, use a cable that meets or exceeds 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 sh]ield 10 ohms per 1000 feet.
If the host does not support RS-485, use an RS-232 to RS-485 conversion box, sourced locally and configured
per manufacturer instructions. To install the MK2200 with a host that does not support RS-485:
1.
Insert the power supply barrel connector into the MK2200 power port. See Figure 1-3 on page 1-5 .
2.
Route the power cable.
3.
Plug the Symbol AC power supply into a wall outlet.
4.
Connect the conversion box to the host using an RS-232 cable.
5.
Connect the RS-485 cable to the LAN port on the MK2200. See Figure 1-3 on page 1-5 for port locations.
Terminate the cable according to the RS-485 Port Connections described in Table 2-3 .
6.
Plug the other end of the RS-485 cable into the converter box.
Use wire nuts or
connector block