I/O Modules
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ADAM 4000 Series User’s Manual
Event counting
The event counter is connected to the Digital Input channel and can
be used to keep track of the total amount of external low-speed pulses.
Its accumulated maximal count is 65535. The count will maintain at
65535 even if the actual number of events exceeds 65535. The counter
can be read or reset to zero by the host computer.
Since the Event counter’s data are not stored in EEPROM, the event
counter is cleared and set to zero after every reset or start up of the
analog input module.
Alarm signaling
Analog input modules include High and Low alarm functions. High
and Low alarm limits may be downloaded into the module’s EEPROM
by the host computer.
The alarm functions can be enabled or disabled remotely. When the
alarm function is enabled, both Digital Output channels are used to
indicate the High and Low alarm state. Digital Output channel 1 (DO1)
equals to High alarm state, and Digital Output channel 0 (DO0) equals
to Low alarm state. The High and Low alarm states can be read at any
time by the host computer.
Every A/D conversion will be followed by a comparison with the
High and Low limit. When the input value exceeds one of these limits,
the High or Low alarm state is set to ON.
There are two alarm mode options, Momentary and Latching. If the
alarm is in Latching mode, the alarm will stay on even if the input value
returns within the limits. An alarm in Latching mode can be turned OFF
by giving a Clear Alarm command from the host computer. A Latching
alarm is cleared by the module when the opposite alarm is set. When
the module receives a value that is lower than the Low alarm limit, it
will clear the High alarm and turn the Low alarm ON.
When the alarm is in Momentary mode, the alarm will be turned
OFF as soon as the input value returns within the limits.
The arrangement of coupling High and Low alarm states with
Digital Output lines may be utilized to build ON/OFF controllers that
can operate without the involvement of host computer.