9.437 Narda-MCP

This page describes the driver configuration and the device window for the Narda-MCP device driver. This driver operates a Narda spectrum analyzer in multi channel power measurement mode. The power of up to twelve channels may be measured simultaneously, the measured values are compared against individual limits.

Device window pages

The following table shows which device window pages are available with this individual device type.

• --- Measurement Display (see below)
• --- Settings (see below)
• --- Faults and fault mask
• --- The device info page.
• --- The maintenance page.

Configuration parameters

At the maintenance page of the device window there are a couple of configuration parameters which must be set to make the software talk to the device.

The Narda spectrum analyzer ist connected to the VLC as a TTY over TCP device, the IP address is specified in the device setup window as the interface name. The default opert number of the Narda spectrum analyzer is 5000.

Measurement display

The Narda-MCP device provides it's own graphical widget presenting the measured channel power values similar to a spectrum display. Each channel power value is shown as a colored bar with it's height telling the power value, it's width reflecting the channel's bandwidth (the width of a channel ist not always truely proportional to the channel bandwidth in order to prevent narrow bandwidth channels to collapse to a single line).

Channels with a power value within the given limits are drawn green, channels below or above their limits are red. Additionally a "noise level" value may be specified, channels below this value are considered to be off an are drawn gray (e.g. for occasional use transmissions where a not present is not treated as a fault.

Settings

At the settings page of the device window, the parameters of the up to twelve channels to measure are defined. For each channel, it's name, the center frequency, the bandwidth and the channel power limit values are set. All values are stored at the sat-nms VLC, not at the device itself.

Beside the channel parameter the "spectrum analyzer like" parameters reference level , scale and resolution bandwidth are defined here as well.

Finally, the special parameter noise level is used to set the display behaviour for channels with very low power. Channels with a power value below the noise level are considered to be switched off explicitly. No "low limit" fault is generated and the channel bar is drawn gray. This way you can differentiate between a "switched on, but power too low" and a "switched off, power doesn't care" condition. If you want a channel with low level to be reported as fault< in any case, set the noise level to a value like -999.9 dB.

Variables defined by this device driver