7
Assembly 101 - Device Readings
Your Alicat device can output up to 20 different
data statistics depending on
the device’s configuration. Default statistics for each device type are specified in
sections 1.3.1 through 1.3.4 below. Each statistic present will increase the size of
the assembly. Assembly size can be determined by doing an explicit messaging
read of the assembly size attribute – class 4, instance 101, attribute 4.
The configured data statistics for assembly 101 can be viewed by directly
connecting to the embedded web server of the device and clicking on the tab
labeled “Data IO”. (See page 12 for information on assigning an IP and connecting
to the web server.)
The value returned for a pressure reading can be absolute pressure, gauge pressure
or differential pressure, depending on your device’s configuration. If you wish to
customize the format and the displayed readings of your device, please speak to
an Alicat applications engineer.
Device status conditions in the device are specified below. Values in parenthesis are
displayed on the display panel of the device. The device status is output as a 32-bit
DWORD. At the present time, bits 13-31 are reserved and should read as zero.
Bit
Description
0
Temperature Overflow (TOV)
1
Temperature Underflow (TOV)
2
Volumetric Overflow (VOV)
3
Volumetric Underflow (VOV)
4
Mass Overflow (MOV)
5
Mass Underflow (MOV)
6
Pressure Overflow (POV)
7
Totalizer Overflow (OVR)
8
PID Loop in Hold (HLD)
9
ADC Error (ADC)
10
PID Exhaust (EXH)
11
Over Pressure Limit (OPL)
12
Flow Overflow During Totalize (TMF)
