Measurement Computing WEB-TEMP - Manual (Page 24)

WEB-TEMP User's Guide Functional Details
24
POWER/COMM LED
The POWER/COMM LED (upper LED) is on when external power is supplied. The WEB-TEMP has an
on-board voltage supervisory circuit that monitors the 5 V external power supply. The table below explains the
function of the
POWER/COMM LED.
LED Indication
On 4.75 V to 5.25 V external power is supplied to the WEB-TEMP.
Off Check the following:
 External power is not supplied; verify that the supply is connected to the external power connector.
 A power fault has occurred. A power fault occurs when the input power falls outside of the specified
voltage range of the external supply (4.75 V to 5.25 V).
LINK/ACTIVITY LED
The LINK/ACTIVITY LED (lower LED) blinks green when a data packet is sent or received over the Ethernet
connection. The table below explains the function of the LINK/ACTIVITY LED.
LED Indication
Blinking Data is being transmitted or received over the Ethernet connection.
On  The Ethernet is idle.
 Your network traffic has reached its maximum limit, and no communication is possible. Check with
your Network Administrator.
Off  The Ethernet cable is not connected to the WEB-TEMP.
 The Ethernet cable is not connected to the network.
 The Ethernet cable is damaged.
 The Ethernet cable is not the correct type (a crossover cable is required for a direct connection.)
Digital logic voltage switch
The digital logic voltage switch lets you set the voltage to either 3.3 V or 5 V (default setting).
To interface with 3.3 V logic, use the 3.3 V setting. To interface with 5 V logic, use the 5 V setting. Refer to the
digital I/O specification on page 34 for the maximum and minimum threshold levels for each setting.
Figure 12. Output voltage switch positions
To change the logic voltage, slide the switch left or right with a screwdriver.
Factory default reset button
Press and hold this button for three seconds to restore the factory default network settings on the WEB-TEMP.
When held for 3 seconds, the
POWER LED will turn off for a short time, indicating a reset is in process. When
the POWER LED turns back on, reset is complete and the factory default network settings have been restored.