[mrtg] Help with mrtg.cfg units conversion

[Mick]

Hi All,

I read in the mrtg documentation that when one uses an external monitoring 
script these are the values that are parsed:
=======================
The external command must return 4 lines of output:
Line 1: current state of the first variable, normally 'incoming bytes count'
Line 2 :current state of the second variable, normally 'outgoing bytes count'
Line 3 :string (in any human readable format), telling the uptime of the 
target.
Line 4: string, telling the name of the target.
=======================

I am not sure if the lines 3 &4 above are important and without them I will 
still be able to graph correctly inputs for the top two lines.  I have 
managed to knock up two scripts which parse two values each.  Script 1 parses 
initial and current ADSL sync speeds, while script 2 parses initial and 
current SNR values of a DSL modem.  The sync speeds are in the 6500 to 7616 
kbits/second range, while the the SNR values are from -1 to +9dB.

Under Options, I have set them up both as gauge, but the MaxBytes must be 
wrong because sync speed shows 60.2kb/s (instead of 7616kbps) and SNR shows 
as 48b/s and this is shown at the very top of the scale (instead of 6.0 dB).

This is my current mrtg.cfg:
=======================
#################################
#       GLOBAL                  #
#################################

WorkDir: /home/michael/http/htdocs/mrtg
WriteExpires: Yes
NoMib2: Yes
#IPv4Only[modem]: Yes
#RunAsDaemon: Yes
#Interval:    5

#################################
#  2WIRE 1800HG Modem           #
#################################
Title[^]:  Traffic Analysis for
Title[modem-sync]: 2WIRE 1800HG BRIDGED MODEM
PageTop[modem-sync]:2WIRE 1800HG sync speed
Options[modem-sync]: bits, gauge, expscale, noinfo, growright, nobanner
Target[modem-sync]: `/usr/bin/perl /home/michael/test.1800HG-v00e1.pl`
MaxBytes[modem-sync]: 12500000


Title[^]:

Title[modem-snrm]:  2WIRE 1800HG SNRM
PageTop[modem-snrm]:2WIRE 1800HG SNRM
Options[modem-snrm]: bits, gauge, expscale, noinfo, nopercent, growright, 
nobanner
Target[modem-snrm]: `/usr/bin/perl /home/michael/test.1800HG-v00e2.pl`
MaxBytes[modem-snrm]: 1250000
=======================

Can you please advise how I can tune the MaxBytes lines, or perhaps my options 
to get the ranges I need?
--  
Regards,
Mick
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