ZWorld Exp-A/D12, User Manual

Page: 14 / 111

XP8500 14 s Overview
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The XP8500 provides 11 channels of 12-bit analog-to-digital (A/D)
conversion, with onboard signal conditioning for four of these channels to
match the input voltage range between 0 V and 10 V. Gain and bias
resistors may be selected and installed by the user to determine the voltage
ranges of the conditioned input signals.
The XP8500 may be operated either in a ratiometric mode (a mode that
reduces errors arising from power-supply variations) or in an absolute
mode (where an onboard precision voltage reference assures accurate
measurements). The printed circuit board has space for optional sensor-
excitation resistors.
Each XP8500 has its zero offset and gain for the four conditioned channels
stored in an onboard, serial EEPROM. An application can use library
functions to access the EEPROM’s calibration constants to correct
measurements for offset and gain error.
The XP8500 receives its power from the 24 V and +5 V. An
onboard voltage regulator develops a clean +5 V supply for the board’s
analog circuitry from the +24 V PLCBus. The same version of the
XP8500 works with both +12 V and +24 V controllers.
Like other Z-World expansion boards, the XP8500 boards can be installed
in modular plastic circuit-board holders attached to a DIN rail. The
XP8500 boards can also be mounted, with plastic standoffs, on any surface
that will accept screws. Up to 16 XP8500 boards addresses are possible
on a single PLCBus.
For ordering information, call your Z-World Sales Representa-
tive at (530) 757-3737.