System Sensor FAAST Modbus - Manual (Page 7)

User Guide: FAAST Fire Alarm Aspiration Sensing Technology® Modbus Protocol Schema 1
7 Rev A0
Reading Logs
In order to read the device logs, the following steps must be followed.
Event Log Read
1. Write the Administrator Password in the Administrator Password holding register.
2. Read the Sensor API status holding register and verify that the ADMIN_UNLOCK bit is set.
3. Write the Event log index value into corresponding holding register using Write Single Holding Register Command
(0x06). The default shall be 1 which reads the latest 40 events.
4. Read Event Logs.
Examples:
a. Total no. of events = 50, Index = 2, then the Event log read command will read last 10 events.
b. Total no. of events = 80, Index = 2, then the Event log read command will read last 40 events.
c. Total no. of events <= 80, Index = 3, then the client shall show Device read failure because there are no events present
in the memory corresponding to given Index value.
Trend Log Read
1. Write the Administrator Password in the Administrator Password holding register.
2. Read the Sensor API status holding register and verify that the ADMIN_UNLOCK bit is set.
3. Write the Trend log index value into corresponding holding register using Write Single Holding Register Command
(0x06). The default shall be 1 which reads the latest one trend log.
4. Read the Trend Log.
Examples:
a. Total no. of trends = 50, Index = 2, then the Trend log read command will read recent but one trend log.
b. Total no. of trends = 80, Index = 80, then the Trend log read command will read last trend log.
c. Total no. of trends = 30, Index >30, then the client shall show Device read failure because there are no trends present
in the memory corresponding to given Index value.
Message Log Read
1. Write the Administrator Password in the Administrator Password holding register.
2. Read the Sensor API status holding register and verify that the ADMIN_UNLOCK bit is set.
3. Write the Message log index value into corresponding holding register using Write Single Holding Register Command
(0x06). The default shall be 1 which reads the latest one message log.
4. Read the Message Log.
Examples:
a. Total no. of messages = 50, Index = 2, then the Message log read command will read recent but one message log.
b. Total no. of messages = 20, Index = 20, then the Message log read command will read last message log.
c. Total no. of messages = 30, Index >30, then the client shall show Device read failure because there are no messages
present in the memory corresponding to given Index value.