Industrial controller | LD485A-MP |
| (ME836A-R5) |
High-Speed Short-Haul Modem-B (SHM-B) Async
•Powered, point-to-point, 4-wire.
•Speeds up to 115.2 kbps.
•Ideal for applications where data speed is crucial.
•Uses two unshielded twisted pairs.
•Includes optical isolation to protect against surge damage.
•Switch-selectable for DTE or DCE equipment.
•Available in both standalone and rackmount card versions. With a pair of High-Speed SHM-B Async units, two RS-232
devices can communicate at speeds of up to 115.2 kbps! Data travels at this rate when the SHMs are configured for
1.5-mile (2.4-km) distances. To get the greatest distance—up to 4 miles (6.4 km) over 24 AWG wiring—set them to operate at 2400-bps speeds.
Along with transmitter and receiver circuits, the High- Speed SHM-B Async includes EIA-232 control-line interfaces, status monitor LEDs, and a loopback switch. The High-Speed SHM-B Async is available in both standalone versions (ME802A or ME802A-R3) and a rackmount card version (ME802C).
Use these SHMs with 4-wire metallic circuits, with twisted- pair cable offering the best performance. And although you can use most types of twisted-pair cable, to achieve maximum performance, we recommend that you use CAT4 or CAT5 UTP cable.
Because there are no voltages greater than ±9 VDC or
17 VAC present on the circuit board of the High-Speed SHM-B Async, it offers maximum operator safety. Receive lines are protected from potential ground differences through optical isolators rated at 2500 volts.
Plus, the SHM offers easy installation. Because it‘s switch- selectable for either DTE or DCE equipment, you won’t need any special cross-pinned cables; it works with the modular RJ cable that’s already installed in your building.
LD485A-MPs (ME836A-R5)
PLCs
RS-232/RS-485 Multipoint Line Driver (LD485A-MP)
•Powered, point-to-point or multipoint, 2- or 4-wire.
•Provides high-speed service (64 kbps) for large multipoint installations (up to 64 drops).
•Works with any DTE that can be polled, regardless of the DTE’s RTS support.
•User-selectable port-timeout feature automatically disables a port once it finishes transmission.
•Operates in 2-wire half-duplex or 4-wire full-duplex mode.
•Maximum distances of 4 miles (6.4 km) at 1200 bps over
24 AWG wire.
Here‘s the ideal line driver for multipoint installations where you want to link many terminals—each with its own line driver—to a computer via one master line driver. Use it, for instance, in high-speed and polling applications. Depending on the operating environment, as many as 64 devices can be linked together using twisted-pair cable.
You can also use the RS-232/RS-485 Multipoint Line Driver in point-to-point installations until you upgrade to a multi- point environment.
And it operates as an RS-232 to RS-485 interface converter, enabling an RS-232 device to transmit data over much longer distances than is normally possible (up to 4 miles at 1200 bps). Although it’s designed specifically to connect to other RS-232/RS-485 Multipoint Line Drivers, you can connect the RS-485 port to any device with an RS-422 or RS-485 interface. Connect, for instance, RS-485 and RS-422 devices to the same LD485A-MP in an industrial application.
The line driver also features a manual loopback test, so you can check the system wiring for both the RS-232 and RS-485 interfaces. In addition, transient protection on the RS-485 interface helps prevent damage from voltage transients on the data line.
