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Configuring IRIG-B Port Parameters for CTP Bundles (CTP Menu)

 

This topic describes how to configure port parameters for IRIG-B daughter cards.

Adaptive clocking is configured by default on IRIG-B bundles, and the packet size is set to 64 bytes. The packet size combined with the default data rate of 16 Kbps produces a packet rate of 32 pps, which is a good packet rate for adaptive clocking.

Before you begin:

  • Disable the bundle before you modify the bundle options.

To configure IRIG-B port parameters using the CTP Menu:

  1. From the CTP Main Menu, select 1) Bundle Operations.
  2. Select 1) CTP.
  3. Select a bundle from the list. The bundle port must have an IRIG-B daughter card installed.

    If you select an active bundle, you are prompted to disable the bundle before configuring it.

  4. Select 3) Port Config.
  5. Select 2) Interface.
  6. Select 1) Type and set the type to Optional Interface: IRIG-B.
  7. Follow the onscreen instructions and configure the options as described in Table 1.

    The options vary depending on whether the bundle is T1 or E1 and whether fractional T1 or E1 is configured.

  8. To configure clocking for the port, select 3) Clock Config and configure the Clock Config option as described in Table 1.

Table 1: CTP Bundle IRIG-B Port Parameter Settings in the CTP Menu

FieldFunctionYour Action

Direction

Specifies the direction of the circuit. Although the IP circuit connection through the network is full duplex, an IRIG-B circuit is actually a simplex application, and the daughter card can operate only in Rx or Tx mode and not both at the same time.

If the autonegotiation setting of the CTP Ethernet media and the far-end switch or router do not match, it is possible for the CTP Ethernet ports to be in a half-duplex state, although the duplex setting is not configurable and always assumed to be full-duplex on the CTP device. Starting with CTPOS Release 7.2, the half-duplex state at CTP network interface card (NIC) ports are acquired, regardless of the duplex setting configured on the far-end node. After the autonegotiation process is completed, if the CTP NIC cannot acquire full-duplex mode, then the interfaces are considered to be down and a log message is recorded in both the /var/log/messages directory and the syslog file stating that the interface is down due to a non-full duplex condition. You are prompted to verify the cable connection, speed, and duplex settings because the NIC link might be down.

Specify yes or no to the question: Is this an IRIG-B source end (IRIB-B signal enters CTP)?

  • Yes (y)—Sets direction to Rx. This end of the circuit recovers IRIG-B from the attached cable and generates IP packets toward the network

  • No (n)—Sets the direction to Tx. This end of the circuit accepts IP packets, extracts the IRIG-B data codes, and transmits IRIG-B signaling output onto the cable.

Output High Level

This setting appears only if you set the direction of the port to Tx.

Specifies the high output level, which is measured in peak-to-peak voltage. This setting is based on a 50-ohm termination

Enter a number from 0.00 through 7.85 volts peak-to-peak.

Output Low Volts Level

This setting appears only if you set the direction of the port to Tx.

Specifies the low output level, which is measured in peak-to-peak voltage. This setting is based on a 50-ohm termination.

Enter a number from 0.00 through 7.85 volts peak-to-peak.

Port Speed (kbps)

Specifies the data rate on the IP connection.

Unless network bandwidth is at a premium, we do not recommend that you change this value from the default of 16 Kbps.

Enter a number from 1000 through 25,500 bps. The port speed must be a multiple of 100 bps.

Clock Config

Specifies the type of clocking for the bundle.

Select one:

  • 4WTO/IRIG - Master End—This end of the circuit generates a clock signal and sends it to the remote end.

  • 4WTO/IRIG - Adaptive End—This end of the circuit receives the clock signal from the remote end. The client clock uses its period to determine when to sample data and how to transmit data across the link.

  • Custom—The custom clocking configuration is used.