Omega Webcam OM-USB-1208FS Manuale Utente
OM-USB-1208FS User's Guide
Functional Details
20
The accuracy plots in Figure 12 are drawn for clarity and are not drawn to scale.
Figure 12. Error band plot
OM-USB-1208FS channel gain queue feature
The OM-USB-1208FS's channel gain queue feature allows you to set up a scan sequence with a unique per-
channel gain setting and channel sequence.
channel gain setting and channel sequence.
The channel gain queue feature removes the restriction of using an ascending channel sequence at a fixed gain.
This feature creates a channel list which is written to local memory on the OM-USB-1208FS. The channel list is
made up of a channel number and range setting. An example of a four-element list is shown in the table below.
This feature creates a channel list which is written to local memory on the OM-USB-1208FS. The channel list is
made up of a channel number and range setting. An example of a four-element list is shown in the table below.
Sample channel gain queue list
Element
Channel
Range
0
CH0
BIP10V
1
CH0
BIP5V
2
CH7
BIP10V
3
CH2
BIP1V
When a scan begins with the gain queue enabled, the OM-USB-1208FS reads the first element, sets the
appropriate channel number and range, and then acquires a sample. The properties of the next element are then
retrieved, and another sample is acquired. This sequence continues until all elements in the gain queue have
been selected. When the end of the channel list is detected, the sequence returns to the first element in the list.
appropriate channel number and range, and then acquires a sample. The properties of the next element are then
retrieved, and another sample is acquired. This sequence continues until all elements in the gain queue have
been selected. When the end of the channel list is detected, the sequence returns to the first element in the list.
This sequence repeats until the specified number of samples is gathered. You must carefully match the gain to
the expected voltage range on the associated channel — otherwise, an over range condition can occur. Although
this condition does not damage the OM-USB-1208FS, it does produce a useless full-scale reading. It can also
introduce a long recovery time from saturation, which can affect the next measurement in the queue.
the expected voltage range on the associated channel — otherwise, an over range condition can occur. Although
this condition does not damage the OM-USB-1208FS, it does produce a useless full-scale reading. It can also
introduce a long recovery time from saturation, which can affect the next measurement in the queue.