Installation
313903B
9
Serial Communication
Remote communication (up to 100 feet) can be
achieved using an RS-232-type port.
Information can be read from, or written to the Sentinel II
by a personal computer (or other intelligent device). This
communication is a master/slave protocol with the Senti-
nel II as the slave and the PC as the master.
NOTE: With the exception of a sign-on message when
powered up, the slave will not send any data or informa-
tion unless requested by the master.
•
Data is sent across the serial port as ASCII charac-
ters with leading zeros suppressed.
•
A BYTE can be up to 3 characters.
•
An INTERGER can be up to 5 characters.
•
Each command and each response is terminated
with a carriage return (CR) (ASCII - Hexadecimal
0D or Decimal 13)
•
If the data is not presented in the correct format, the
command is not executed. Note that a “read” should
be made after doing a “write” to verify the proper
action has taken place.
NOTE: Changes made through the serial link are active
but not permanent until the “save to E
2
” command (WC)
is issued. If the WC command is not issued, turning the
power off and on restores the originally saved operating
parameters. See page 26 for recommended, user sup-
plied, communication port connectors.
Serial Communication Wiring
•
The Serial Communications are wired through a
6-point header on 0.1 inch centers (F
. 9).
•
Only three pins (1 - 3) are used (See Table 1).
•
The other end of this cable may be connected to a
personal computer.
✓
Pin 1 (nearest to the transformer) is the signal
ground.
✓
Pin 2 is an output that connects to received data
at PC.
✓
Pin 3 is an input that connects to transmit data
of the PC.
Table 1: Serial Pin Data
Pin #
Description
PC
DB-9F
PC
DB-25F
1
Signal Ground
5
7
2
Read Data
2
3
3
Send Data
3
2
F
IG
. 9
SERIAL PORT PLUG
1 SIG COMMON
2 READ DATA (OUTPUT)
3 XMIT DATA (INPUT
4
5
6
TO PC SERIAL PORT
2 RCV DATA (INPUT)
3 XMIT DATA (INPUT)
5 SIGNAL GROUND
2 XMIT DATA (OUTPUT)
3 RCV DATA (INPUT)
7 SIGNAL GROUND
SERIAL
1
6
J1
Summary of Contents for 562870
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