SMS2000 and Property Management Systems
TUT Systems, Inc Page 84 of 104 P/N 220-06288-20
Note: For more information on using the set pms-server command, see the SMS2000
Command Reference.
Protocol Modes
All PMS protocols (except Micros-Fidelio) work in one of three modes:
TTY
ACK-NAK
ENQ-ACK-NAK
TTY provides best effort delivery, while ACK-NAK and ENQ-ACK-NAK provide
reliable message delivery.

TTY MODE

In TTY mode, message delivery is best effort only. The SMS2000 sends the message to
the PMS and does not look for any response. The message contents are sent followed by
a newline character.
SMS -> This is the first message\r\nThis is the second message\r\n
PMS does not reply.
\r is the C program escape for CR (Carriage Return), which is ASCII code 13
(0x0D).
\n is the C program escape for LR (Line Feed), which is ASCII code 10 (0x0A).
SMS -> indicates that the SMS2000 sends this message. It is not a part of the message.
The message format is based on the interface type. The format is slightly different for
standard HOBIC as compared to GEAC.

ACK-NAK MODE

In ACK-NAK mode, message delivery is reliable and the PMS must acknowledge receipt
of the message within a specific time frame (or the SMS2000 sends it again).
SMS -> <STX>This is the first message<ETX><bcc>
PMS -> <ACK>
SMS -> <STX>This is the second message<ETX><bcc>
PMS -> <ACK>
<STX> is the ASCII character STX, which is ASCII code 2 (0x02).
<ETX> is the ASCII code ETX, which is ASCII code 3 (0x03).
<ACK> is the ASCII code ACK, which is ASCII code 6 (0x06).
<bcc> is a binary checksum character.