Sel SEL-DTA2, Instruction Manual

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3.2
SEL-DTA2 Instruction Manual
Date Code 20020329
Communications
Serial Port Connections and Configurations
Serial Port Connections and Configurations
Two serial port connectors on the SEL-DTA2 rear panel are labeled Port 1 and
Port 2. Both adhere to EIA-232 data communications standards.
Port 1 is intended for local communications via a personal computer, printing
terminal, or other device.
Port 2 of the SEL-DTA2 should be connected to a relay port set for automatic
message or DTA support.
The port baud rates are set with jumpers accessed by removing the top cover.
Available rates are 300, 600, 1200, 2400, 4800, and 9600. SEL-DTA2 baud
rates must match those set for the relay.
NOTE:
Do not set the SEL-DTA2 baud
rate higher than 2400 bps when
connected to an SEL-300 series relay.
The maximum effective data processing rate for the SEL-DTA2 when
connected to an SEL-300 series relay is 2400 bps. Setting a higher data rate
results in loss of communication data and may cause the SEL-DTA2 to halt all
communication.
The serial data format is:
8 data bits
2 stop bits (SEL-DTA2 Firmware Revisions: 100–400)
or
1 stop bit (SEL-DTA2 Firmware Revisions: 500–800)
No parity
This format cannot be altered. Table 3.1 shows serial port pin assignments and
signal definitions. Refer to Command Characteristics on page 3.4 to see
details of the VERSION command and a method to determine the firmware
revision of your SEL-DTA2.
Table 4.1 on page 4.1 in Section 4: Installation lists cables that connect to Port
1 and Port 2.
Table 3.1 Serial Port Pin Assignments
Connector
Pin
Signal Description
1 +5 Vdc +5 volt output (enable with JMP 3, see Figure 4.2 on page 4.3
in Section 4: Installation ).
2 RXD Receive data input.
3 TXD Transmit data output.
4 +12 Vdc +12 volt output (enable with JMP 2, see Figure 4.2 ).
5 GND Ground.
6 –12 Vdc –12 volt output (enable with JMP 1, see Figure 4.2 ).
7 RTS The SEL-DTA2 asserts this line under normal conditions.
When its received-data buffer is full, the line deasserts until the
buffer has room to receive more data. Connected devices
should monitor RTS (usually with their CTS input) and stop
transmitting characters whenever the line deasserts. If trans-
mission continues, data may be lost.
8 CTS The SEL-DTA2 monitors CTS and transmits characters only
when CTS is asserted.
9 GND Ground.