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Connecting Reference Inputs and Network Interface

NetClock 9400 can synchronize to various external inputs (such as GPS, NTP, PTP, and/or a user set time). Depending on the desired operation and specific NetClock configuration, connect the GPS, or other external references (NTP input reference and “user set time” are software configurations that require no additional physical connection to NetClock. These two reference inputs are discussed later in this manual).

  1. GPS Reference input: Typical installations include GPS as an external reference input. If the GPS receiver is not installed or if the GPS will not be used as a NetClock reference, just disregard the steps to install the GPS antenna and associated cabling.
  2. Install the GPS antenna, surge suppressor, antenna cabling, and GPS preamplifier (if required). Refer to the documentation included with the Model 8225 GPS antenna for additional information regarding GPS antenna installation.

    Connect the GPS cable to the rear panel antenna input jack (refer to LINK). Until the GPS antenna is connected to the rear panel jack, the Antenna Problem alarm is asserted, causing the front panel “Fault” light to be blinking orange (the Antenna Problem alarm indicates an open or short exists in the antenna cable). Unless there is an open or short in the antenna cable, the Fault light should stop flashing orange once the GPS antenna and coax cable are connected to the rear panel. If the Fault light does not stop flashing after connecting the antenna, see LINK GPS troubleshooting reception issues

  3. PTP Reference input: With the available PTP option card configured as a slave synchronizing via Ethernet/RJ-45 to a PTP master.
  4. Network interface to LAN: Obtain the following network information from your network administrator before continuing:
Available static IP Address This is the unique address assigned to the NetClock unit by the network administrator. The default static IP address of the NetClock unit is
Subnet mask (for the network) The subnet mask defines the number of bits taken from the IP address that are used in the network portion. The number of network bits used in the net mask can range from 8 to 30 bits.
Gateway address The gateway (default router) address is needed if communication to the NetClock is made outside of the local network. By default, the gateway is disabled.

Required Network information


If your network does not support DHCP, use the front panel LCD and keypad (see Front Panel Keypad, and Display) to input the desired static IP, subnet mask, and gateway address.

Network Bits Equivalent Netmask Network Bits Equivalent Netmask
30 18
29 17
28 16
27 15
26 14
25 13
24 12
23 11
22 10
21 9
20 8

Subnet mask values