System Sensor FAAST Modbus - Manual (Page 6)

User Guide: FAAST Fire Alarm Aspiration Sensing Technology® Modbus Protocol Schema 1
6
Device Sensor Status and Control Operations (Cont’d)
Device Time
In order to set the time, the following steps must be followed:
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. If it is set, the Sensor API
Command Register is enabled and will process commands issued.
3. The Modbus client writes the new time value using Epoch/UNIX timestamp formate to the time holding registers through
Write Multiple Register Command(s).
4. Write the Save Time Command value, 0xEE22 in the Modbus Specific configuration Command holding register in order
to save the new time.
5. The device stores and applies the new device time.
6. Read the Modbus Specific configuration Command holding register. The value will be 0x0000 when the Command
completes successfully.
7. Write 0x0 to the Administrator Password in the Administrator Password holding register if no further changes are
desired.
Device Smoke Reference
The device may be programmed with a reference in order to compensate for a period of high particulate due to a change in ambient
environmental conditions. Use the following steps to modify the Device Reference:
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. If it is set, the Sensor API
Command Register is enabled and will process commands issued.
3. The Modbus client writes the new Reference Value in 32-bit Float format to the Smoke Reference Value register through
Write Multiple Register Command.
4. The device applies the new Reference.
5. Read the Sensor Smoke Reference Value to verify it stored correctly.
6. Write 0x0 to the Administrator Password in the Administrator Password holding register if no further changes are
desired.
Modbus Administrator Password
The Modbus Administrator Password grants the user the privilege of writing to the Holding Registers. This password is the same as
the User Interface Button Lockout Code. It is not readable through the Modbus Interface. It is set to ‘1111’ as the default. The values
may range from 1111 to 9999. The user may change the password by performing a Device Configuration Change as described
earlier.
A failure to gain administrator privileges due to a forgotten or lost password is a recoverable event by using the PipeIQ software,
connecting to the device and updating the device configuration with a known password.