Lucent Technologies DEFINITY Enterprise Communications Server And GuestWorks Property Management System Interface Specifications

							Feature Description 
19 Line Control Characteristics 
DEFINITY ECS and GuestWorks Property Management System
Interface Specifications  555-231-601  Issue 2
December 1999
Feature Description
Line Control Characteristics
The hardware data link consists of an EIA RS232C-D serial data electrical inter-
face extended from a switch data channel. The link interface appears as a data 
communications equipment (DCE) unit (CCITT definition) with the attributes 
shown in Ta b l e 1
. See Figure 1 and Ta b l e 2 for more details about the switch-to-
PMS link.
Table 1. Link Interface Attributes
Item Description
Data Rate 1200, 2400, 4800, 9600 bps
(+1.0%, -2.5%) nominal asynchronous
 Maximum Message Rate (2-way)*Smallest message size — 20 msg/sec
Largest message size — 2 msg/sec
 Operating Mode Full Duplex Only
Electrical Interface Signal Form 
(See Table 2
)EIA RS232C - Type D
Electrical standard compatibility
EIA RS404
 Interface Distances (maximum) From switch to 8400B/7400A — 3500-5000 ft.
From switch to ADU
1200 bps — 20000 ft.
2400 bps — 12000 ft.
4800 bps — 7000 ft.
9600 bps — 5000 ft.
From 8400B/7400A/ADU to PMS — 50 ft.
Word Framing (see Figure 2
) 10 bits (1 start, 8 data bits, 1 stop)
Parity Options No parity
Maximum Message Text† 13 Frames (N)
33 Frames (T)
47 Frames (A)
* The rate may vary with different values in the “Milliseconds Before PMS Link 
Acknowledgement Timeout” field.
† Data Link Escape (DLE) characters are not included. 
						

							DEFINITY ECS and GuestWorks Property Management System
Interface Specifications  555-231-601  Issue 2
December 1999
Feature Description 
20 Line Control Characteristics 
!CAUTION:
For the switch to recognize when the PMS link is down, the following inter-
face leads must be controlled signals: Request to Send (CA), Clear to Send 
(CB), Data Set Ready (CC), Received Line Detect (CF), and Terminal 
Ready (CD).
Figure 2. Message Word Frame Table 2. PMS Interface Lead Designations
Lead* Pin Number Function Source
AA 1 Frame Ground Common
BA 2 Transmitted Data PMS
BB 3 Received Data Interface
CA† 4 Request to Send PMS
CB† 5 Clear to Send Interface
CC† 6 Data Set Ready Interface
AB 7 Signal Ground Common
CF† 8 Received Line Detect Interface
CD† 20 Terminal Ready PMS
* An 8400B/7400A supports all of these leads. An ADU does not support Pin 4, and
Pins 5, 6, and 8 are driven by one lead tied together.
† These must be valid controlled signals. 
						

							DEFINITY ECS and GuestWorks Property Management System
Interface Specifications  555-231-601  Issue 2
December 1999
Feature Description 
21 Line Control Characteristics 
Message Envelope
The envelope for the message text uses the following ASCII encoded characters:
nSTX: Start of data text, 0x02 (Decimal 2)
nETX: End of data text, 0x03 (Decimal 3)
nBCC: Block check code.
The character-oriented protocol used for communications exchange uses the 
following ASCII encoded characters:
nACK (Acknowledgement): Message acknowledged by receiver, 0x06 
(Decimal 6)
nNAK (Negative Acknowledgement): Message not acknowledged by 
receiver, 0x15 (Decimal 21)
nENQ: Sender request for the last ACK/NAK from receiver, 0x05 
(Decimal 5).
An 
octet is the 8-bit text field of a 10-bit word frame which excludes Start and Stop 
(see Figure 2
).
The control character frames use an entire octet for one ASCII encoded character 
(the most significant or 8th text bit is always a logical 0 - the STX is 0000 0010 in 
binary). The standard message text frames (not containing guest names) consist 
of two 4-bit characters per frame called nibbles (see Figure 3
, Figure 4, Figure 5, 
and Ta b l e 3
). Except for the control characters, the ASCII mode uses the standard 
ASCII character set.
Message text frames containing guest names (Check-in with Name, Guest 
Information Input/Change, and Room Image) will interpret the eight data bits as 
two 4-bit nibbles in all frames not containing ASCII-encoded name characters (T) 
(A).
Every time you send a message (STX at the beginning), you increment the 
message counter by one. The message counter is relative to the sender; both the 
switch and the PMS have message counters, and they may initialized to start an 
any value within the allowed range. For example, if you received message #5 last 
time, you should expect to receive message #6 the next time. 
						

							DEFINITY ECS and GuestWorks Property Management System
Interface Specifications  555-231-601  Issue 2
December 1999
Feature Description 
22 Line Control Characteristics 
Figure 3.Message Format — Frame 2 (Normal Mode)
Figure 4. Message Format — Frame 2 (Transparent Mode) 
						

							DEFINITY ECS and GuestWorks Property Management System
Interface Specifications  555-231-601  Issue 2
December 1999
Feature Description 
23 Line Control Characteristics 
Figure 5.Message Format — Frame 2 (ASCII Mode) 
						

							DEFINITY ECS and GuestWorks Property Management System
Interface Specifications  555-231-601  Issue 2
December 1999
Feature Description 
24 Line Control Characteristics 
Table 3. Data Encoding of Message Text Nibbles
Va l u e4-Bit Encode
(Normal and
Transparent)8-Bit Encode
(ASCII)
0 0000 0011 0000
1 0001 0011 0001
2 0010 0011 0010
3 0011 0011 0011
4 0100 0011 0100
5 0101 0011 0101
6 0110 0011 0110
7 0111 0011 0111
8 1000 0011 1000
9 1001 0011 1001
(Note 1) 1010 (Normal Only) N/A
* (Note 2) 1011 0010 1010
# (Note 2) 1100 0010 0011
NULL 1111 0010 0000 (Note 3)
Note 1: The 0 encode is transmitted as “1010” in the normal 
mode and converted to “0000” by the receiver.
Note 2: The “1011” and “1100” encodes are used to represent
the “*” and “#” characters on the telephone keypads.
Note 3: ASCII space is Hex 20.
N/A = Not applicable. 
						

							DEFINITY ECS and GuestWorks Property Management System
Interface Specifications  555-231-601  Issue 2
December 1999
Feature Description 
25 Line Control Characteristics 
The general PMS message layout is shown in Figure 6.
Figure 6. PMS Message Layout
Each message block will be terminated by a BCC octet. The BCC is an exclusive 
“OR” of all octets following the STX through and including the ETX (the STX is not 
included in the BCC calculation). Figure 7
, Figure 8, and Figure 9 show examples 
of messages. The BCC is used to insure message integrity. 
						

							DEFINITY ECS and GuestWorks Property Management System
Interface Specifications  555-231-601  Issue 2
December 1999
Feature Description 
26 Line Control Characteristics 
Figure 7.Example Message — Normal Mode 
						

							DEFINITY ECS and GuestWorks Property Management System
Interface Specifications  555-231-601  Issue 2
December 1999
Feature Description 
27 Line Control Characteristics 
Figure 8.Example Message — Transparent Mode 
						

							DEFINITY ECS and GuestWorks Property Management System
Interface Specifications  555-231-601  Issue 2
December 1999
Feature Description 
28 Line Control Characteristics 
Figure 9.Example Message — ASCII Mode