Adds Single Channel Analog in or out to a PLC, Field Re-Configure Signal Range
The MSP family of analog I/O blocks offers
the freedom to use any analog sensor with many models of PLC. Each
MSP block provides
a single analog input (or output) interface between the PLC and the
analog world. Communications between the MSP unit and the PLC is through
a patented protocol that provides truly "open" architecture for analog
signals to be processed digitally.
The MSP is factory preconfigured to support a specific
analog input or output signals, depending on the model. Optionally,
the MSP signal
range can be reconfigured in the field using the Windows® based
configuration software model SCC-CC-A1 (sold separately).
Input Analog Signal
The analog input signal is isolated, filtered, amplified, scaled and/or linearized
by the MSP micro-processor and converted to a 16-bt, binary weighted, digital
word which is transmitted serially (one bit at a time) at 24 VDC signal levels
to the PLC’s discrete I/O port. At the PLC, each binary-weighted bit sent
to the discrete input is temporarily stored until all 16 bits have been received.
The digital word is then reassembled and its value (proportional to the analog
signal) is placed in a working register of choice for decision making by
the PLC program.
Output Analog Signal
The numerical value representing a desired analog output signal is placed into
a PLC working register of choice. This value is transmitted serially (one bit
at a time)at 24 VDC signal levels to the MSP through the PLC ’s discrete I/O
port. The MSP scales, linearizes and proportionally converts the digital signal
to the voltage or current output signal. The signal is then sent to the isolated
output channel for use
by a analog actuator connected at the output channel.