# Configuring NETREF (NETREF1) and NETREF2

If you specified that any board use NETREF (NETREF1) or NETREF2 as a timing reference, you must configure one or two other boards to drive the signals. Configure a different board for each signal. The source for each signal can be a digital trunk.

Note: NETREF2 is available only in H.110 configurations.

Use the following keywords to configure a board to drive NETREF (NETREF1):

Keyword | Description
--- | ---
Clocking.HBus.NetRefSource | Specifies the source of the NETREF (NETREF1) timing reference. Set to any of the following: NETWORK to drive NETREF based on the signal from a digital trunk connected to the board. STANDALONE if the board will not drive NETREF. OSC to drive NETREF using the board's oscillator for debugging purposes only.
Clocking.HBus.NetRefSourceNetwork | If Clocking.HBus.NetRefSource is set to NETWORK, specifies the number of the trunk from which to get the signal.
Clocking.HBus.NetRefSpeed | Sets the speed of the NETREF signal. Set to 8K.

Use the following keywords to configure a board to drive NETREF2:

Keyword | Description
--- | ---
Clocking.HBus.NetRef2Source | Specifies the source of the NETREF2 timing reference. Set to any of the following: OSC to drive NETREF2 using the board's oscillator. NETWORK to drive NETREF2 based on the signal from a digital trunk connected to the board. STANDALONE if the board will not drive NETREF2.
Clocking.HBus.NetRef2SourceNetwork | If Clocking.HBus.NetRefSource is set to NETWORK, specifies the number of the trunk from which to get the signal.
Clocking.HBus.NetRef2Speed | Sets the speed of the NETREF signal. Set to 8K.

Note: Not all boards can drive NETREF or NETREF2. Refer to the board documentation for more information.