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

							DEFINITY ECS and GuestWorks Property Management System
Interface Specifications  555-231-601  Issue 2
December 1999
Feature Codes, Process Codes, and Operations 
89 Status Inquiry and Failure Management 
Recovery from Loss of Communication
In the case of a PMS failure, it is assumed that check-in/check-outs may need to 
be done manually and entered into the PMS system at a later time when the sys-
tem is again operational. The PMS should not resume transmission of the process 
code F Status Inquiry message to reestablish communication until the database 
has been brought to as current a status as possible. This is to prevent the prema-
ture transmission of incorrect data to the switch via the database exchange 
update procedure.
In the case where the PMS has remained operational during a data link failure, the 
PMS should continue to attempt to send the Status Inquiry process code F 
messages. A Status Inquiry response (one of process codes 0, 1, or 2) from the 
switch will indicate that communication has been reestablished.
A process code 0 response indicates that the switch has had no status changes 
during the data link failure period and that the switch has automatically switched 
back to the normal operating mode “data link active” (switch-activated check-in/
check-out disabled).
A switch response of process code 1 indicates that the switch has had at least 
one uncommunicated status change and that the PMS should initiate a database 
room image exchange to synchronize the databases.
A switch response of process code 2 indicates that the switch has failed and that 
status memory has been initialized with each RSN in the following status:
Room Status = Occupied
Controlled restriction level = nonrestricted state
Message Waiting Lamp = off
Guest name (T) (A) = BLANK
Coverage Path (T) (A) = No coverage
In response to the receipt of a status inquiry message that has a process code 
of 1 or 2, the PMS must immediately initiate a database swap. The database 
swap must include either of the following:
nAll rooms
nVacant rooms plus occupied rooms with:
— Message Waiting
— Restrictions
— Populated name fields (T) (A)
— Coverage paths (T) (A) 
						

							DEFINITY ECS and GuestWorks Property Management System
Interface Specifications  555-231-601  Issue 2
December 1999
Feature Codes, Process Codes, and Operations 
90 Status Inquiry and Failure Management 
The Database Exchange Procedure
If the switch has recognized the reestablishment of communication and 
responded with a process code 1 or process code 2 message to the PMS, the 
switch will not process any message type received from the PMS, except Status 
Inquiry messages, until the PMS initiates the database exchange procedure.
The PMS has control of when a database exchange will be initiated, which RSNs 
will be included in the exchange, and which status items will be supplied to the 
switch for update for each room. However, after the switch requests a Database 
Swap (process code 1 or process code 2), the switch expects the database swap 
to start. For DEFINITY, if the PMS sends ten messages that are not status inquiry 
messages before sending the process code 3 message, the switch will log an 
error, attempt to send a process code 5 message, and eventually tear down the 
link. The switch will continue to use process code 1 or process code  2 status 
inquiry messages until the PMS sends a process code 3 database message.
The PMS indicates the start of the database room exchange by transmitting a 
process code 3 Status Inquiry message to the switch. The receipt of the process 
code 3 message in the switch indicates the following to the switch:
1. A database room exchange will commence, and
2. Transmission of normal status changes can be reinitiated.
After transmission of the process code 3 message, the PMS should then transmit 
the room data exchange image message (17,3) (N), (37,3) (T), or (27,3) (A) for 
each room for which synchronization is required. Note that some time delay may 
be necessary between each room data image message so that the maximum 
message rate for the data link is not exceeded, and to provide “space” for normal 
status change feature messages.
For telephones that are part of a suite check-in group, the database swap will 
update the status of all telephones in the switch, regardless of their current state 
(occupied or vacant).
The switch will process each room data image (17,3) (N), (37,3) (T), or (27,3) (A) 
message and return the complement room data image message (17,4) (N), (37,4) 
(T), or (27,4) (A) in response as soon as the LAT occurs. This allows the PMS to 
use ENQ characters as described in “Room Data Image” starting on page 72
.
“Check-In/Check-Out” starting on page 65
, “Room Change/Room Swap” starting 
on page 79, and “Guest Information Input/Change” starting on page 81 also 
describe switch handling. 
						

							DEFINITY ECS and GuestWorks Property Management System
Interface Specifications  555-231-601  Issue 2
December 1999
Feature Codes, Process Codes, and Operations 
91 Status Inquiry and Failure Management 
As mentioned previously, normal feature messages may be sent or received 
during the database room image exchange procedure. Care should be taken to 
insure that the most current status is always presented via message sequence 
for a particular room to the switch. For example, a status change done at a PMS 
terminal may occur simultaneously with the access of the data for the room data 
image message for that particular room. If the switch were to receive the “new” 
individual feature message, followed by the room data image with the “old” status 
value, the switch would set its status to the “old” status value, leaving the two 
databases out of synchronization. Correct message sequencing and data access 
should be done to eliminate this possibility. The PMS can assume that the switch 
will send the most current individual status change or most current data in the 
(17,4) (N), (37,4) (T), or (27,4) (A) message response.
When the database exchange room image (17,3) (N), (37,3) (T), or (27,3) (A) 
messages have been sent and returned with (17,4) (N), (37,4) (T), or (27,4) (A) 
messages processed by the PMS for all rooms requiring synchronization, the 
PMS indicates the end of the database update procedure by transmitting a 
process code 4 message to the switch.
The receipt of a process code message is necessary for the switch since the 
switch has a threshold of three database synchronization procedures that are 
started but were unable to complete due to succeeding data link failures. This 
may be the case where intermittent yet persistent problems exist which preclude 
the basic database update procedure from ever completing, leaving the data link 
in a continual failure/recovery (thrashing) state. After a link drop causes the count 
to be exceeded, the switch logs an error. Two test commands that try to establish 
the link are as follows:
ntest pms-link — tries to bring the link back up.
ntest pms-link long — tries to bring the link down then back up.
The PMS may initiate a database exchange procedure at any time provided that a 
database update procedure is not currently active. If such a situation arises (either 
by error detection within the PMS or by receipt of a process code 1 or process 
code 2 Status Inquiry response from the switch), the PMS should send a process 
code 4 Database Exchange Complete message before restarting the procedure. 
						

							DEFINITY ECS and GuestWorks Property Management System
Interface Specifications  555-231-601  Issue 2
December 1999
Feature Codes, Process Codes, and Operations 
92 Status Inquiry and Failure Management 
Examples of Status Inquiry Message Activity
Ta b l e 2 7 is an example of the status inquiry message activity that might occur dur-
ing normal traffic to initialize the data link communication when a database swap 
is requested by the switch (the process code follows the status inquiry).
The following chart shows an example of status inquiry message activity for the 
Normal, Transparent, and ASCII modes. Table 27. Example of Status Inquiry Message Activity
Originator Message Explanation
PMS (70, F) (N) (T) (null) or
(71,F) (A) (null)“Are you there” message from the PMS.
Switch ACK Acknowledgment from the switch.
Switch (70, 1) (N) (T) or (71,1) (A) 
or
(70, 2) (N) (T) or (71,2) (A)Message indicating that database swap should 
begin.
PMS ACK Acknowledgment from the PMS.
PMS (70, 3) (N) (T) or (71,3) (A) Start database exchange message from the PMS.
Switch ACK Acknowledgment from the switch.
PMS (37,3) (N) (T) or (27,3) (A) Room image message from the PMS.
Switch ACK Acknowledgment from the switch.
Switch (37,4) (N) (T) or (27,4) (A) Database update status message from the switch.
PMS ACK Acknowledgement from the PMS.
PMS (70, 4) (N) (T) or (71,4) (A) End of database exchange.
Switch ACK Acknowledgment from the switch. 
						

							DEFINITY ECS and GuestWorks Property Management System
Interface Specifications  555-231-601  Issue 2
December 1999
Feature Codes, Process Codes, and Operations 
93 Status Inquiry and Failure Management  
						

							DEFINITY ECS and GuestWorks Property Management System
Interface Specifications  555-231-601  Issue 2
December 1999
Feature Codes, Process Codes, and Operations 
94 Status Inquiry and Failure Management  
						

							Acronyms and Glossary 
95 Acronyms 
DEFINITY ECS and GuestWorks Property Management System
Interface Specifications  555-231-601  Issue 2
December 1999
Acronyms and Glossary
Acronyms
This section contains acronym expansions related to the PMS interface specifica-
tion.
nACK — Acknowledge message (0x06)
nASCII — American Standard Code for Information Interchange
nBCC — Block check code
nBCD — Binary coded decimal
nCKI — Check-in (ASCII)
nCKO — Check-out (ASCII)
nCR — Controlled restriction (ASCII)
nDLE — Data link escape (0x10)
nENQ — Inquiry message (0x05)
nETX — End of text message (0x03)
nGIC — Guest information input/change (ASCII)
nHKR — Housekeeper status from room (ASCII)
nHKS — Housekeeper status from designated station (ASCII)
nID — Identifier
nLAT — Link acknowledgment timer
nLIT — Link idle timer
nMR — Maximum retransmissions
nMRR — Maximum retransmissions request
nMSG — Message Waiting (ASCII)
nMSGCT — Message count
nNAK — Negative acknowledgment message (0x15)
nNOP — No operation
nRMC — Room change/room swap (ASCII) 
						

							DEFINITY ECS and GuestWorks Property Management System
Interface Specifications  555-231-601  Issue 2
December 1999
Acronyms and Glossary 
96 Glossary 
nRMI — Room data image (ASCII)
nRR — Data Link Release Reason Code
nRSN — Room station number
nSTS — Status inquiry (ASCII)
nSTX — Start of text message (0x02)
nV/O — Vacant/Occupied
Glossary
This section contains glossary terms related to the PMS interface specification.
nAttendant Console — Telephone equipment usually used at the front desk 
to answer calls and perform services such as wakeup calls.
nBackup Telephone — Switch telephone that is administered with console 
permissions, usually has a display, is used to answer calls at the front desk, 
and is used to access features such as Automatic Wakeup and Do Not Dis-
turb.
nBlock Check Code — An exclusive “OR” of all octets following the STX 
through and including the ETX (the STX is not included in the calculation).
nNULL — In normal or transparent mode, NULL is defined as Hex f 
(Octet 1111) for all fields except the name field. For the name field, NULL is 
d e f i n e d  a s  H e x  3 f  ( O c t e t  0 0 11  1111 ) .  
In ASCII mode, NULL is defined as Hex 20 (Octet 0010 0000) for all fields.
In transparent and ASCII mode, NULL in the name field of the room data 
image message is defined as Hex 3f (Octet 0011 1111).
See page 15
 for an explanation of how NULLs are used in coverage paths.
nOctet — The 8-bit text field of a 10-bit word frame. This does not include 
the Stop and Start bits.
nPadding Characters — These are characters used to fill out empty spaces 
in a data field when the required number of characters are not transmitted. 
Room station numbers, which are right-justified, are padded out with 0s 
(zeros). For transparent and ASCII mode, the Name field (left-justified) is 
padded with spaces (Hex 20) and the Coverage Path field (left-justified) is 
padded with Hex f.
nPMS Terminal — Data terminal usually kept at the front desk where guests 
are checked in and checked out. 
						

							DEFINITY ECS and GuestWorks Property Management System
Interface Specifications  555-231-601  Issue 2
December 1999
Acronyms and Glossary 
97 Glossary 
nRoom Numbering Plan — This is the numbering plan for the rooms and 
how they relate to the telephone extension numbers assigned for those 
rooms.
For example, in a hotel that has more than nine floors and no more than 99 
rooms on each floor, floors one through nine would use a prefix digit (for 
example, 3) prepended for each room extension number. For example, to 
call Room 405, a user would dial 3405.
For floors ten and higher, the actual room number would match the exten-
sion number since the room numbers are four digits long. For example, 
Room 1235 uses extension 1235.
nRoom Station Number — Room Station Number (or RSN) is equivalent to 
the room extension number or room telephone number. However, the 
actual room number will not necessarily match the extension number of the 
telephone in the room. See Room Numbering Plan.
nSpace — In Normal mode, Space is not used.
In transparent and ASCII mode, Space is defined as Hex 20 
(Octet 0010 0000). 
						

							DEFINITY ECS and GuestWorks Property Management System
Interface Specifications  555-231-601  Issue 2
December 1999
Acronyms and Glossary 
98 Glossary