Instruction manual

ControlWave Micro Instruction Manual (CI-ControlWave Micro)
2-16 Installation Revised Jun-2013
trigger an external alarm or annunciator if the ControlWave Micro
enters a “watchdog” condition in which the CPU cannot control your
process.
A watchdog condition occurs when:
 A watchdog timer expires. This happens if the ControlWave project
execution halts unexpectedly – “program crash.”
 The controller powers up but is not yet running the ControlWave
project.
 The CPU module detects that the regulated 3.3 Vdc or 1.8 Vdc
supplies are out of specification.
A MOSFET switch activates the watchdog connector whenever a
watchdog condition occurs.
Terminal Block
Connector TB2
You must power the watchdog connector (TB2) from an external power
supply. Unplug removable connector TB2 from the PSSM and wire
power to the connector. We recommend you do not plug the connector
back into the PSSM until the CPU module is already installed in the
housing.
TB2 provides two watchdog MOSFET switch connections:
 TB2-1 = VI - Watchdog MOSFET Switch Input
 TB2-2 = VO - Watchdog MOSFET Switch Output
The VI input on TB2 powers the watchdog switch; its switched output
connects to the VO output on the same terminal block. You must
reference the external power source connected to the VI terminal to the
return point of the input source powering the PSSM (which is either –
VIN or PSGND on TB2). See Figure 2-12.
Figure 2-12. Watchdog MOSFET Switch Wiring