P/N 3100346 ISSUE 3
PAGE 7
<00>
Two byte ASCII ‘00’ used as protocol padding (two byes)
<ZONE>
Programmable unit zone character. Range ASCII A-D. (1byte)
<ETX>
The <ETX> character has a value of 3 hexadecimal and is required at the end of
every message (1 byte)
<CHKSUM>
Optional two byte Message Block checksum (2 bytes). Refer to Section 4.0 for
Block checksum calculation and verification. If checksum is not desired, must pad
these two bytes with two ASCII zeros 00.
Unit Response: <STX><UA>43<STATUS><ZONE><ACK><ETX><CHKSUM>
<UA>
Unit address, ASCII Range 00-1F (two bytes)
<43>
Two byte ASCII Command echoed back from receiving unit (2 byte).
<STATUS>
Unit’s current diagnostic state. Range ASCII A - D. (1byte)
A = Tone/Message is active and Local Power is absent
B = Tone/Message is active and Local Power is present
C = Tone/Message is not active and Local Power is absent
D = Tone/Message is not active and Local Power is present
<ZONE>
Unit's programmed zone character
<ACK>
This <ACK> character has a value of 6 hexadecimal and represents
acknowledgement of the received command with valid checksum (1byte).
Note:
In the event that a bad checksum is calculated, by the receiving unit, it will reply with a <NAK>
character instead. The <NAK> character has a value of 15 hexadecimal.
<ETX>
The <ETX> character has a value of 3 hexadecimal and is required at the end of
every message (1 byte)
<CHKSUM>
Receiving unit calculates two-byte checksum and returns ASCII value. Refer to
Section 4.0 for Block checksum calculation and verification.
Example 1:
<STX>014300A<ETX>00
Unit 01 is being polled and programmed to Zone A
Unit Response: <STX>0143DA<ACK><ETX>56
The unit returned a <STATUS> ‘D’ for its current diagnostic state and an <ACK>
character because both message and checksum are valid. The unit is not actively
playing Tone/Message. The calculated two-byte message checksum was ‘56’.
Example2:
<STX>014300A<ETX>00
Unit 01 is being polled and programmed to Zone A. Unit 01 is currently playing a
Tone/Message.
Unit Response: <STX>0143BA<ACK><ETX>54
The unit returned a <STATUS> ‘B’ for its current diagnostic state and an <ACK>
character. The unit is actively playing a Tone/Message at the time this command
was received. The calculated two-byte message checksum was ‘54’.
3.4
TIME SEQUENCE, TIME REMAINING COMMAND - 44
Send Format:
<STX><UA>44 00 <ZONE> <ETX> <CHKSUM>
<UA>
Unit address characters (2 bytes). See Section 2.0, Messaging Format
<44>
Two byte ASCII Command denoting a Time Sequence (2 bytes).
<00>
Two byte ASCII ‘00’ used as protocol padding (two byes)
<ZONE>
Programmable unit Zone issued by the master or controlling computer
Range ASCII A-D (1 byte).
<ETX>
The <ETX> character has a value of 3 hexadecimal and is required at the end of
every message (1 byte)
