Analog Outputs; Serial Expansion I/O; Adding Modules - Elpro Technologies 915U-2 User Manual

915U-2 Wireless I/O
• Deadband (Default) - If the Analog Input is greater than the Upper Set
point, the set-point status will be active (on, "1"). The setpoint will reset
(off, "0") when the Analog Input is less than the Lower Set Point. Note that
the Upper Set Point must always be higher than the Lower Set Point."
• Windowed – If the analog value is inside the upper and lower setpoints,
the setpoint will be active (on, "1"), and if the analog value is outside of
these setpoints the setpoint will be reset (off, "0")
Invert –This option toggles the Setpoint control logic between the default normal and
inverted state. The function does not change, only the operation is inverted, e.g. if
setpoint is on in its normal state, inverting the signal will mean the setpoint will be off in
the normal state.
Window – This option toggles the Set point operation between the default Dead band
and Windowed modes.
Scaling – The software shows the input scaling in either Low-High Values or Zero-Span
values. These variables will change the Scale of the Analog Inputs.
• Low – The low Engineering value for the Input
• High – The high Engineering value for the Input (mA, V, Hz, etc)
• Zero – Starting Value (counts) when measured value is zero
• Span – Number of counts per measured value (mA, V, Hz, etc)
The Analog is a linear scale with an overall Raw range of 8192 to 49152 decimal (Total
= 40960). The input Engineering range can have many different forms i.e. 0-20mA, 0-
5V, or 0-1000Hz which is why the zero and span can be scaled to give the correct Raw
range.

Analog Outputs

Name – The inputs can be named to help with configuration or use the default, up to 30
characters including spaces.
Failsafe Time (sec) – The Fail Safe Time is the time the output needs to count down
before activating the failsafe state. Receiving an update or a COS message will reset
the Fail Safe Timer back to its starting value. If the Fail Safe Timer gets down to zero
then the output will be set to the Fail Safe state (mA)
It is recommend this Fail Safe Time be configured for a little more than twice the update
time of the input that is mapped to it, that way the output will reset if it fails to receive
two update messages. Entering a zero in the Fail Safe Time will disable.
Failsafe value (mA) – The value that you wish the output to be set to on completion of
the failsafe timeout.

4.2.6 Serial Expansion I/O

Adding modules

Additional 115S serial expansion I/O modules can be added if more I/O is required.
When connecting expansion I/O module to the 915U-2 the RS485 serial port is
configured to communicate Modbus protocol by default.
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User Manual