1.665 TX-OFF-Timer

This page describes the device driver and the device window for the TX-OFF-Timer device. This device switches off a running transmission at a preprogrammed time within 24 hours. The device also controls an external LCD unit which displays the remaining time of the transmission.

Usage

The timer gets started by entering the desired stop time in the format hh:mm . Times in the past are assumed to refer to the next day. While running, the timer sets a flag 'running' which may be used to conditionally enable other M&C functions. When the timer expires, it issues the TX-OFF command defined at the device's maintenance/setup page.

Cisco 2800GSM Interface

The device may be configured to listen to some status variables of a Cisco 2800GSM / VPN router. The state of the VPN tunnel and the GSM receive level (RSSI) value gets displayed in the LCD and the info.gsmstate parameter.

Device window pages

The following table shows which device window pages are available with this individual device type. Tool-bar functions not mentioned here are described at the general description of device windows .

Configuration parameters

At the maintenance page of the device window there are a couple of configuration parameters which must be set to integrate the device into the VLC/M&C.

parameter description
txOffId The message ID of the parameter controlling the RF ON/OFF state of the transmission, e.g. EIRP.on .
txOffCmd The command / value to be sent to the message id defined above in order to switch off the transmissions. In most cases this will be OFF .
txOffDisplay The text to be shown in the external display while the timer is stopped. The default is OFF
showBars If set to YES, the GSM receive level of the attached Cisco VPN router gets displayed as 0 to 5 bars, similar to a mobile phone display. NO makes the display show the level as digits 0..5.
gsmRssiId The message ID telling the RSSI level to display, with a Cicso 2800GSM router something like: CICSO.c3gCurrentGsmRssi . Expects a level value in dBm to be reported with this parameter.
gsmVpnStatId The message ID telling the VPN tunnel state. With a Cisco 2800GSM router e.g. CISCO.rttMonLatestRttOperSense
gsmRssiTable This table is used to translate the RSSI level value (dBm) into 0 to 5 bars in the display. The table consists of 5 integer numbers, separated by commas. The first value defines the level necessary to show one bar, the second one is the minimum value for two bars and so on. If you supply less than five values, the device automatically fills the list in 3dB steps.
Serial Remember to set the line parameters for the serial interface connected to the LCD unit ( 9600,N,8,1 ).

NMS-VLC clock difference compensation

The TX-OFF-Timer takes the clock difference between NMS and VLC into account when calculation the (local) end time of a transmission. The transmission gets stopped at the programmed end time in terms of NMS time. This calculation may interfere with the clock adaption being done by the VLC's clktrim daemon. The latter tunes the VLC clock to run faster or slower about up to 10 minutes/day until the VLC clock matches the NMS time. The clock difference between VLC and NMS by and by becomes smaller. Hence, with large VLC clock deviations, the effective end time may differ from the NMS time. It is recommended not to use the clktrim daemon for VLCs which are only occasionally running for this reason.

Using the TX-OFF-Timer without the LCD unit

The TX-OFF-Timer also may be used without the external LCD unit. To do this, configure the TX-OFF-Timer with a 'null' interface and the 'Logical' protocol in the VLC's device setup. The TX-OFF-Timer will not occupy a serial interface when configured in this way.

Variables defined by this device driver

name type flags range
info.driver TEXT R/O StringRange R/O
info.type TEXT R/O StringRange R/O
info.port TEXT R/O StringRange R/O
info.frame TEXT R/O StringRange R/O
info.timeDiff INTEGER R/O IntegerRange R/O (0 .. 0)
info.gsmstat TEXT R/O StringRange R/O
config.txOffId TEXT SAVE SETUP StringRange
config.txOffCmd TEXT SAVE SETUP StringRange
config.txOffDisplay TEXT SAVE SETUP StringRange
config.showBars CHOICE SAVE SETUP EnumRange (YES NO)
config.gsmRssiId TEXT SAVE SETUP StringRange
config.gsmVpnStatId TEXT SAVE SETUP StringRange
config.gsmCommFaultId TEXT SAVE SETUP StringRange
config.gsmRssiTable TEXT SAVE SETUP StringRange
txOffTime TEXT StringRange
remainingTime TEXT R/O StringRange R/O
running BOOLEAN R/O BooleanRange R/O (true false)
extended BOOLEAN R/O BooleanRange R/O (true false)
extendPossible BOOLEAN R/O BooleanRange R/O (true false)
extend TEXT StringRange
gsmstat TEXT StringRange