Intermec Transaction Manager 9560, Руководство пользователя

Страница: 38 / 309

9560 Transaction Manager User’s Manual
2-10
Connecting to a Data Collection System
You can connect the 9560 into a data collection system in one of three ways:
• Connect to a computer only
• Connect to a computer and terminal
• Connect to a port concentrator or system unit with or without a terminal
Before connecting the data collection system, be sure your system meets the
interface requirements listed next.
Cable Interface Requirements
You can connect the 9560 to an RS-232, RS-422, or 4-wire RS-485 multi-drop
interface. The type of cabling depends upon the distance between the 9560 and
the other components of the system, as shown in the following table.
Maximum Distance Preferred Interface
50 feet RS-232
2000 feet RS-485 multi-drop (use only with a 9161A Option 2 multi-
drop concentrator or 9154 Line Controller)
4000 feet RS-422
RS-232 is designed for short distances and is generally not used for long data
lines. It can be used successfully over longer distances if there is a “clean”
electrical environment in the building. Because RS-232 connects the two signal
grounds of the units together, any ground noise is coupled directly to the units.
RS-232 cables longer than 50 feet are susceptible to noise and may cause data
transmission problems. To avoid problems with longer RS-232 cables, you can
install modems at each end of the cable. Modems isolate the equipment
grounds from the cable and reduce noise. Follow the modem manufacturer’s
instructions for terminating the cable, and be sure that the modem has
transformer coupling or optical isolation.
RS-422 uses balanced transmission to provide noise immunity. The
transmission is received with a differential receiver, and the receiver signal
ground is not common with the cable.
Note: If you use RS-422 or RS-485 wiring, you must configure the 9560 for the
chosen interface. The default is RS-232.
For information about host protocols and interface considerations, see
Chapter 5, “Data Communications and Operating Options.”