User`s guide

Universal Library User's Guide Temperature Input Boards - WEB-TEMP, WEB-TC
194
Digital channels that are configured as alarms will power up in an output state. When an alarm is activated,
the associated DIO channel is driven to the output state defined by the alarm configuration. The alarm
configurations are stored in non-volatile memory on the device and are loaded on power up. Alarm settings
can be configured using the device's web browser or InstaCal.
Pacing temperature readings
The internal update rate for temperature measurement is a fixed value for these devices. If the UL reads the
device faster than the internal update rate, temperature readings "repeat." For example, if using cbTIn() in a
loop to measure a rapidly changing temperature, readings do not change for several iterations of the loop, then
"jump" when the update occurs internally.
Using single sensors with cbTInScan() (WEB-TEMP only)
When using single sensors for RTD or thermistor sensors, you should ignore the data for channels that do not
have sensors attached. It is best to use cbTIn() for these configurations, since you can select which channels
to read. If you use cbTInScan(), however, data for all channels over the entire range of channels are returned.
Since some channels are not populated in this configuration, filter out the data for channels without sensors.
Channel names
You can specify a custom name for each of the device channels with InstaCal. Enter up to 10 alpha-numeric
characters in the Name text box on each channel configuration page.
Saving configuration settings
InstaCal allows you to save hardware configuration settings to a file, or load a configuration from a previously
saved file.
Each WEB-TEMP channel can be configured to measure temperature data collected by one of five categories
of temperature sensors: thermistors, thermocouples, RTDs, semiconductors, and Disabled. Each WEB-TC
channel can be configured to measure temperature data collected by one of eight types of thermocouples.
Recommended warm-up time
Allow the WEB device to warm-up for 30 minutes before taking measurements. This warm-up time
minimizes thermal drift and achieves the specified rated accuracy of measurements. For RTD or thermistor
measurements, this warm-up time is also required to stabilize the internal current reference.
Calibration
You can manually calibrate a WEB device using InstaCal or the web interface. Any time a sensor is changed
using the WEB interface, a calibration is automatically performed. If the device has not been warmed up when
this occurs, you should re-calibrate after the specified warm-up time.
Timeout errors
In some cases, there can be delays in obtaining the data from the WEB device, causing a NOREMOTEACK error to
be generated. This can be caused by other users making configuration changes on the device, or by slow or
busy network connections.
You can use the ConfigItem option BINETIOTIMEOUT with cbSetConfig() to set the time (in mS) to wait for
a device to acknowledge a command or query made via the network connection.
FlashLED()
Call this function to flash the POWER/COMM LED on a WEB device. This is useful if you have multiple
devices connected and you want to identify a particular device.