www.miinet.com
Moore Industries-International, Inc.
- 48 -
User’s Manual
238-741-00K
May 2019
Programmable Smart HART Temperature Transmitter
THZ
3
/ TDZ
3
SECTION 4
Trigger: This determines what triggers a message to be sent to the host. The trigger source value
depends on the HART command and is defined above.
There are three parameters which need to be set for the trigger - mode, level and units
Mode
Level
Units
Description
Continuous
1.0***
Not used
Messages will be sent every x seconds where x is the
Update period
Window
positive value
set*
Messages will be sent if the reading increases or
decreases
by
the
window
value
Rising
any**
set*
Messages will be sent if the reading is above the
trigger
value
(High
alarm)
Falling
any**
set*
Messages will be sent if the reading is below the
trigger value (Low alarm)
On Change
1.0***
Not used
Used for command 48 to detect any status change
*Units must match the trigger source units. If the units do not match then trigger mode becomes inactive.
** The trigger level can be any value in the trigger source range.
*** For continuous and level modes the trigger level and units are not applicable. The level is set to 1.0 by
default.
In all cases, burst messages are sent every x seconds (Update Period) if the trigger condition is
met. If the trigger condition is not met, the update time will drop to the Maximum Update Period.
Slots 1-8: For commands 9 and 33, the Device Variables which will be sent in the message
need to be selected. By default all slots are set to ‘Not Used’. Only Slots 1-4 can be assigned for
Command 33.
If a trigger condition is set, Slot 1 must have a Device Variable assigned and this will be used as
the trigger source.
Burst message examples:
Read PV every second
Burst message settings: HART command 1:Read PV
Update period: 1 second
Maximum update period: 1 second
Trigger Mode: Continuous
Trigger Level: 1.0
Trigger Units: (250) Not Used
Read Dynamic Variables and Loop Current every second when PV exceeds 50degC or
every 5 minutes (when PV does not exceed 50degC)
HART command 3: Read Dynamic Variables and Loop Current
Update period: 1 second;
Maximum update period: 300 seconds
Trigger Mode: Rising
Trigger Level: 50.00
Trigger Units: degrees Celsius
