All Tracker instruments have alarm output options with volt free relay contacts and TTL outputs on some models. On the panel meters an alarm state message can be flashed on the display along with the measured value.

The following instruments have alarm outputs and options:

• Tracker 211 4-Digit Low Cost, 1 C/O as standard, optional +1 C/O +1 N/O
• Tracker 222 4-Digit High Accuracy, 2 C/O as standard
• Tracker 224 5-Digit High Accuracy, 2 C/O as standard
• Tracker 244 5-Digit Load Cell Indicator, 2 C/O as Standard
• Tracker 245 5-Digit Load Cell Indicator, 4 TTL outputs as standard
• Tracker 254 5-Digit Melt Pressure Indicator. 2 C/O as standard
• Tracker 255 5-Digit Melt Pressure Indicator, 4 TTL outputs as standard
• Tracker 264 5-Digit LVDT Indicator, 2 C/O as standard
• Tracker 265 5-Digit LVDT Indicator, 4 TTL Outputs as standard
• Tracker 284 5 Digit Timer / Counter, 2 C/O as standard
• Tracker 285 5-Digit Timer / Counter, 2 TTL outputs as standard
• Tracker 321 & 332 DIN Rail, +4 C/O when 341 logic expansion module fitted
• Tracker 331 DIN rail, 1 N/O as standard, +1 N/O option, +4 C/O with 341

C/O = Volt free Change Over contacts, N/O = Volt free Normaly Open contacts

On the Tracker 211 low cost series the following alarm parameters are available.

• Alarm Type - None, High, Low
• Alarm message display - On Off (For all alarms)
• Setpoint (max 3 alarms)
• Hysteresis

All other instruments (per alarm):

• Alarm Type - None, High, low, Deviation (band)
• Setpoint (max 4 alarms)
• Deviation High
• Deviation Low
• Latching - On Off
• Output selection (Which outputs switch if any)
• On Delay (Seconds)
• Off Delay (Seconds)
• On Hysteresis
• Off Hysteresis
• Edit Setpoint - On Off (Operator access at run time)
• Alarm Message display - On Off
• Relays energised or de-energised in the alarm state

The hysteresis facility stops noisy signals switching outputs rapidly (relay chatter).

High and low deviation creates a band around the setpoint value. The alarm will be activated if the measured value is out of this band.

On and off delay times can be set to stop fleeting alarms. The measured value must be continuously in the alarm condition for the time set before the alarm becomes activated.

Individual alarms configured as latching or non-latching. Latched alarm require to be acknowledged by the front panel push buttons or, on models fitted with status inputs, via remote volt free contacts.