160 HC900 Process & Safety Controller User and Installation Manual Revision 6
21 April 2017
Table 22 – Controller Operating Modes
Functions in selected mode
I/O scanning (Controller and Expander Racks)
Function block execution; outputs are set according to function block algorithms.
Monitoring of Diagnostics (controller rack and I/O expander racks)
Detection of I/O Modules
Other functions permitted:
Downloading of configurations
Indications of Forces at Status LEDs on I/O modules
Other functions NOT permitted:
AI calibration
AO calibration
I/O scanning (Controller and expansion Racks is performed, but function blocks are
not executed, and all outputs (digital and analog) are set to OFF. (See Note 1.)
Monitoring of Diagnostics (Controller and Expander Racks)
Detection of I/O Modules
Other functions permitted:
AI calibration
AO calibration
Downloading of configurations
Downloading controller firmware (Program Locked or Program)
Other functions NOT permitted:
Indications of Forces at Status LEDs at I/O modules
IO scanning (Controller and Expander Racks) is performed, but function blocks are
not executed, and all outputs (digital and analog) are Frozen (see Note 2) at the
states they were in when the OFFLINE mode was selected.
Monitoring of Diagnostics (local and expanded racks)
Detection of I/O Modules
Other functions permitted:
AI calibration
Indications of Force at Status LEDs of I/O modules
Other function NOT permitted: AO calibration
Note 1: The Off state of the module outputs are defined as:
Digital output - low state
Time proportional Output (TPO) : 0% duty cycle
PPO and TPSC Outputs: Both Fwd and Rev are Off.
Analog output: 0.0 mA
Note 2: The Frozen states of module outputs are defined as:
Digital output: same state as previous (last active state)
Time Proportional Output (TPO): Same duty cycle as in last active state
PPO and TPSC Outputs: digital outputs are Off to freeze the motor position.
Analog output: same current as previous (last active current level)