Analog Input - ABB Symphony Harmony Series Instruction

Analog Input

AIN-120
AIN-200/220
AIN-300
WBPEEUI240751C0
operational. If the backup I/O module has detected a problem
such as an Hnet communication failure, I/O channel failure,
and IFP or LFP field power failure, then no failover will occur.
When a failover occurs due to a non catastrophic failure of the
primary module, the primary will halt with LEDs one and two
on. When a failover occurs due to a catastrophic failure (i.e.,
FAULT lit), an error code will display on LEDs one through
eight of the primary module. Refer to Table
tion of the LED status codes.
For analog input capable blocks, channels are directly wired in
parallel to both I/O modules (Figs.
across an input of one I/O module due to an I/O block fault
will not allow either I/O module to read the input. An open in
an input channel circuit of the base will not allow either I/O
module to read the input.
Failures detectable by an AIN-120 module that cause a failover
to the backup module include:
Multiplexer failure.
•
Amplifier failure.
•
A-to-D converter failure.
•
Bad voltage reference.
•
Channel failure or out of range.
•
Failures detectable by an AIN-200/220 module that cause a
failover to the backup module include:
Amplifier failure.
•
A-to-D converter failure (one per channel).
•
Opto-coupler failure.
•
Bad voltage reference.
•
Bad TC cold junction reference (A-to-D and RTD).
•
Channel failure or out of range.
•
The AIN-300 block has special circuitry to disconnect the RTD
current source on the backup I/O module during normal oper-
ation. This prevents two current sources from being connected
to the RTD at one time. Failures detectable by an AIN-300
module that cause a failover to the backup module include:
Amplifier failure.
•
Analog Input
8-3 for a descrip-
4-1 through 4-7). A short
4 - 3