GE Corometrics 170 Series Service Manual page 199

Cabling Information
Standard RS-232C Rules
Cable Distance
Data Terminal Equipment Cabling
Data Communications Equipment Cabling
Revision C
Peripheral Devices: RS-232 Connectors
Monitor RS-232 Connector
The 170 Series Monitor's RS-232C Ports each use an 8-pin RJ-45 connector, shown
in Figure 8-4.
The following control signals are supported:
Request to Send (RTS): This output line is asserted (+12 V) whenever the 170
Series Monitor is on and operating; it can be used to determine whether the
monitor is powered on.
Transmit Data (TXD): This output line provides the serial data sent to the
external computer from the 170 Series Monitor.
Clear to Send (CTS): This input line must be asserted in order to enable the
transmission of data from the 170 Series Monitor. Under conditions where no
modem is used, the line can be tied to the RTS line of the monitor. If a modem
is used, this line should be tied to the CTS line of the modem.
Receive Data (RXD): This input line provides the serial data sent from the
external computer to the 170 Series Monitor.
The following rules must be observed:
When a direct connection is made between a 170 Series Monitor and another
Data Terminal Equipment (DTE), a standard null-modem cable must be used.
When an indirect connection is made, using a modem, a 170 Series Monitor
requires a normal-modem cable.
The RS-232C Interface supplied with the 170 Series Monitor is capable of operating
over varying distances depending upon the data rate used and whether the cabling is
shielded or unshielded. Refer to the manufacturer's specifications.
When the 170 Series Monitor is directly connected to another Data Terminal
Equipment (DTE) device, a standard null-modem cable is required as shown in
Figure 8-5.
When the 170 Series Monitor is connected to a Data Communications Equipment
(DCE) device (a modem), a standard normal-modem cable is required as shown in
Figure 8-6.
170 Series Monitor
2000947-004
8-17