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DL8000 Preset Instruction Manual
Revised February-2016
Modules
3-39
EIA-232 (RS-232) uses point-to-point asynchronous serial
communications and is commonly used to provide the physical interface
for connecting serial devices, such as gas chromatographs and radios to
the DL8000. The EIA-232 (RS-232) communication provides essential
hand-shaking lines required for radio communications, such as DTR and
RTS.
The EIA-232 (RS-232) communications includes LED indicators that
display the status of the Receive (RX), Transmit (TX), Data Terminal
Ready (DTR), and Ready To Send (RTS) control lines.
Table 3-12
defines the built-in EIA-232 (RS-232) terminals at the
Comm2 port and their function signals.
Table 3-12. Built-in EIA-232 (RS-232) Signal Routing – Comm2
Signal
LED Function
Terminal
RX
Lit when Comm2 is currently receiving.
1
TX
Lit when Comm2 is currently transmitting.
2
RTS
Lit when Comm2 ready to send is not active.
3
DTR
Lit when Comm2 data terminal ready is active.
4
GND
Common.
5
The EIA-232 (RS-232) communications module provides for EIA-232
(RS-232C) signals on the Comm3, Comm4, or Comm5 port depending
on where the module is installed. See
Table 3-13
.
Table 3-13. EIA-232 (RS-232) Communication Module Signal Routing – Comm3, Comm4, and
Comm5
Signal
LED Function
Terminal
RX
Lit when module (Comm3, Comm4, or Comm5) is currently receiving.
1
TX
Lit when module (Comm3, Comm4, or Comm5) is currently transmitting.
2
RTS
Lit when module (Comm3, Comm4, or Comm5) is ready to send is not active.
3
DTR
Lit when module (Comm3, Comm4, or Comm5) data terminal ready is active.
4
GND
Common.
5
3.3.6 EIA-422/485 (RS-422/485) Serial Communications Module
EIA-422/485 (RS-422/485) communication modules meet all EIA-
422/485 (RS-422/485) specifications for differential, asynchronous
serial communication transmissions of data over distances of up to 1220
meters (4000 feet). EIA-485 (RS-485) communications are commonly
used to multi-drop units on a serial network over long distances using
inexpensive twisted-pair wiring.
EIA-422 (RS-422) drivers are designed for party-line applications
where one driver is connected to, and transmits on, a bus with up to ten
receivers. EIA-422 (RS-422) allows long distance point-to-point
communications and the drivers are designed for true multi-point
applications with up to 32 drivers and 32 receivers on a single bus.