Analog Output Circuit; Status Led Indicator - ABB Symphony Harmony Series Instruction

Status Data
Logic Power
Bus Fault Timer
Status LED Indicators
WBPEEUI240769B0
uses this data to verify that the outputs are correct. Each bit
corresponds to one output; a logic one indicates an active (on)
output, a logic zero indicates an inactive (off) output.
Status data is an eight-bit data value that identifies the I/O
module and indicates the default values set by the analog out-
put default jumpers. The controller reads the identification
bits (four MSB) to verify the I/O expander bus communication
integrity and controller configuration. It reads the default bits
(four LSB) to determine the default states set for the analog
outputs in the event of a time-out.
Logic power (+5 VDC and ±15 VDC) drives the I/O module cir-
cuits. It connects through the top 12-pin card edge connector
(P1) shown in Figure 2-1. P3 supplies +24 VDC to operate the
analog output circuits.
The bus fault timer is a one-shot timer that is reset by the I/O
expander bus clock; the controller generates the bus clock. If
the bus clock stops (indicating a controller error), the bus fault
timer times out in 10 milliseconds. This will disable the digital
outputs and set the analog outputs to their default values (set
by jumpers). A red front panel status LED indicates a bus fault
time-out.
Two front panel I/O module status LED indicators show the
operating state of the I/O modules. Circuits on the I/O module
determine the module status and light the appropriate LED.
Refer to Section 4 for explanations of the LED indications and
to Section 5 for corrective actions.
Logic Power
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