Hach ORBISPHERE K-M1100, User Manual

Page: 69 / 116

68
Inputs/Outputs Menu
Analog outputs
There are three analog outputs available. These outputs are configurable in terms of function, content,
and behavior through the instrument menus. Analog outputs are used to output a current which is a
function (e.g. a linear characteristic) of a measurement: AOut =
f (M). The analog outputs can be
typically connected to a PLC. Knowing the function ( f ), the PLC can compute the value of the
measurement.
Instrument
configuration • Select analog output range of current:
4-20 mA or 0-20 mA
• The 4-20 mA range (recommended) allows for an extended event
indication mode that can be selected and configured (default = standard
mode)
For some events (sensor out, purge failure, etc.) the actual measurement is
not significant, but the PLC needs to know how the analog output behaves
in these cases. Two "Event indication modes" are available:
• Standard mode (default)
• Extended mode
Standard event
indication
Refer to Table 1 Standard event indication below.
Extended event
indication The "Extended event indication" mode is only available when the 4-20 mA
output is selected. In this mode, the range between 0 mA and 4 mA is used
to indicate selected events. The events are defined using the channel
configuration option. Refer to
Channel configuration on page 69 .
Table 1 Standard event indication
Analog output
Event output range
Event
0-20 mA 4-20 mA
Gas concentration 20 mA 20 mA
• Channel out
• Sensor out
• Thermal cut-off
• Interfering gas error
Temperature 20 mA 20 mA
• Channel out
• Sensor out