User manual

905U-G Wireless Gateway User Manual
Page 107 ©September 2004
Alarm Indication
MSAL1_ALARM_IND: Command Number = 0022h
This message indicates that a DPV1 slave has transferred an Alarm message to the master.
This message is sent spontaneously by the 905G, i.e. the module itself initiates the message
instruction in the “Spontaneous Message OUT Area” (see “Message Interface Addressing”
above).
Detailed information about the alarm cause is presented in extended words 1-3 and the
message data field, see below.
The 905G may be configured to automatically provide a response to this command (default),
or the response may be provided externally via the message interface. The response will
trigger the module to send an MSAC1_Alarm_Ack to the slave. This will tell the slave that
the master has configured the alarm. The slave will in turn respond with a confirmation
message, see “Alarm Confirmation (MSAL1_ALARM_CON)” below.
Command and response layout:
Command Response
Message ID
(ID) (ID)
Message Information
4002h 0002h
Command Number
0022h 0022h
Data Size
(request length) 0000h
Extended Word 1
Slave Add Slot No -
Extended Word 2
Seq Number
Alarm Spec
Ack
-
Extended Word 3
Alarm Type Ext Diag -
Extended Word 4
- -
Extended Word 5
- -
Extended Word 6
- -
Extended Word 7
- -
Extended Word 8
Fault Information -
Message data byte 1
Data 1
:::
:::
Message data byte n
Data n
• Slave Address
Station address of the slave that indicates the alarm
• Slot Number
Used by the slave to indicate the source of the alarm.
Range 0 -254
• Seq Number
Unique identification number of the alarm.