Oldham WX16, User Manual

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WX16 User Manual | 14
numbers define the location of the variable representing the input value and
must be obtained from the manufacturer of the ModBus RTU device.
•
Our 10-0288 Radio Modem may be connected to the ModBus RS-485 master
port to enable wireless communication to OLCT 200 wireless sensor
transmitters.
EDIT toggles the Data From entry between Analog, Analog with Local Cal or Sensor
Direct, WIRELESS RF900 and ModBus RTU (signed, unsigned & floating point) .
Analog should be selected when the channel’s input comes from a transmitter or
monitoring device with a calibrated output such as 4-20mA. Analog with Local Cal is
available when the WX16 will be the point of calibration for the analog input. Sensor
Direct is identical to Analog with Local Cal and both activate the WX16’s Cal Mode
features (see section 2.2.7). Problems may arise if calibrations are performed in two
places upon the same signal, so Cal Mode menus are only visible when
Sensor Direct
or Analog with Local Cal is selected. These selections should only be used when the
input originates from a non-calibrated signal source such as the Bridge Sensor Input
option described in section 3.1.3. These applications require the WX16 to be used as
the calibration point, since the sensors have no
zero or span controls.
Figure 2.4
2.2.4a Min / Max Raw Counts Menus
The Min Raw and Max Raw counts entries included in Input Data From: menus define
the range of input counts that provide
Measurement Range read-out values described
in section 2.2.6b. This menu entry is determined by the A/D converter resolution of the
channel’s input. For example, if the input is a 10 bit ModBus device with zero at 200
counts and 100% at 1000 counts, then this menu’s MIN should be set at 200 and MAX
at 1000. If communicating with the WX16’s optional 12 bit Analog Input PCB, the MIN
should be 800 and the MAX 4000.
If the input device’s resolution is unknown, the live counts variable on the bottom of the
screen displays actual raw A/D counts currently being read by this channel. This
reading may be used to test the input device for what A/D counts are provided for zero