Specifications

CR3000 Overview
FIGURE OV1-3. Serial Communication Interfaces
OV1.2.3 Computer RS-232
The CR3000 has an isolated RS-232 port.
Direct connection of the CR3000 to a PC is most conveniently done through
the "Computer RS232" port (Figure OV1-3). Table OV1-2 gives a brief
description of each "Computer RS232" pin.
The Computer RS-232 port is a DCE device when connected to a PC with a
serial cable. It also doubles as a DTE device when connected to a modem
device through a null-modem cable. (DTR function is on pin I, Ring is an
input).
Maximum input = ± 25V
Minimum Output = ± 5V
Typical Output = ± 7V
Serial communications is not reliable over cable greater than 50
feet in length.
TABLE OV1-2. Computer RS-232 Pin-Out
ABR = Abbreviation for the function name
PIN = Pin number
O = Signal Out of the CR3000 to a RS-232 device
I = Signal Into the CR3000 from a RS-232
device
PIN ABR I/O Description
1 DTR O data terminal ready
2 TX O asynchronous transmit
3 RX I asynchronous receive
4 not connected
5 GND isolated ground
6 O connected to pin
7 CTS I clear to send
8 RTS O request to send
9 RING I ring
The CR3000 is supplied with a six foot 9-pin to 9-pin serial cable and a 9- to
25-pin adapter to facilitate connection to a PC RS-232 port.
NOTE
Pin 1
COMPUTER
RS232
(TRANSFORMER
ISOLATED)
Pin 5
CS IO)
Pin 6
Pin 9
OV-6