OPTO 22 G4LC32ISA-LT, User Manual

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G4LC32ISA-LT User’s Guide 3-9
CONNECTING TO A HOST PC, MODEM, OR OTHER DEVICE
The G4LC32ISA-LT features an ISA bus and two built-in serial ports: COM0 and COM1. Both serial
ports are RS-232- or RS-485/422-configurable, and have a data transfer rate of 300 Bd to 115.2
KBd. They may be used to communicate to I/O units, intelligent serial devices, or function as
generic communication ports.
Either the ISA bus or COM0 may be used as a primary host port. COM1 may only be used as an
alternate host port. (An alternate host port is an additional host port besides the primary host port.
This could allow, for example, a modem connection from an offsite terminal to dial-up and view the
local process.) The typical G4LC32ISA-LT application uses the ISA port as its host port. A G4LC32ISA-
LT may also be part of a multi-dropped network of controllers in which its COM0 is connected to a
host PC with an AC37.
RS-232 COM0 and COM1 configured ports allow modems, intelligent serial devices, and multiple
G4LC32ISA-LT host ports to be used. Both ports can be programmed and controlled through
OptoControl, and can be configured to p5 VDC for devices with low current demands,
such as barcode readers.
RS-485/422 COM0 and COM1 configured ports may be used as a serial link to connect to Opto 22
I/O units. The G4LC32ISA-LT can be separated by up to 3,000 ft. from I/O units or controllers. (An
AC38 repeater enables even longer separation distances.) This is accomplished via a single shielded
twisted-pair cable that provides communication over an RS-485/422 serial data bus. Up to 32 remote
I/O units (256 with repeaters) can be attached on a single serial link.
Fusing for RS-232 +5 VDC
A +5 VDC fused source is available on pin 1 from both the COM0 and COM1 ports. A maximum 0.5A
load can be drawn through the 1A-rated fuse. The replacement part number for this fuse is Opto 22
P/N FUSE01G4 (Wickman P/N 19373A). Keep in mind that any power drawn should be figured into
the load on the PC’s power supply.
Figure 3-8 shows the location of these fuses:
Figure 3-8: Location of +5V fuses on the G4LC32ISA-LT
INSTALLATION AND SETUP