Xylem XL Series H-522 - Plus - Manual (Page 195)

XL™ Series
Operation with the GOES Radio 16-39
16.11 GOES Downlink Message Header Basics
At times a user must look at the raw data sent from the satellite to see if things are working
properly. The first part of the message is very important to understand as it may help identify
problems at a site. Below is an actual message sent from a site.
163708DE08078184903G51+1NN021EUB00023BCT@DZ@DY@Dc@Db@Dm@Dxj
Now lets break this down to understand it better.
The first 8 characters are the site ID or DPC address. They are shown in bold below.
163708DE 08078184903G51+1NN021EUB00023BCT@DZ@DY@Dc@Db@Dm@Dxj
The next two bytes are the year. In this case the 08 is for 2008.
163708DE 08 078184903G51+1NN021EUB00023BCT@DZ@DY@Dc@Db@Dm@Dxj
The next 3 bytes are the julian day. In this case 078 and is March 18 , on a leap year.. th
163708DE08 078 184903G51+1NN021EUB00023BCT@DZ@DY@Dc@Db@Dm@Dxj
The next 6 bytes is the time the transmission was received. This should be within the assigned
time window. In this transmission it was at 18 hours, 49 minutes and 03 seconds.
163708DE08078 184903 G51+1NN021EUB00023BCT@DZ@DY@Dc@Db@Dm@Dxj
The next byte indicates if the transmission was received properly, the “G’ indicates ‘Good’.
Other possibilities are ‘P’ for parity errors and ‘?’ for unknown errors.
163708DE08078184903 G 51+1NN021EUB00023BCT@DZ@DY@Dc@Db@Dm@Dxj
the next two bytes show the signal strength of the signal received at the satellite. In this case it is
51 which is real good. Numbers in the high forties is good, lower forties is fair and if at 35 or
less, it is surprising the transmission is making it to the satellite.
163708DE08078184903G 51 +1NN021EUB00023BCT@DZ@DY@Dc@Db@Dm@Dxj
The next two bytes indicate if there is any frequency drift. A plus 0 is ideal indicating no drift.
In this case the +1 indicates a positive drift of 50 Hz from the center frequency. For each count,
1, 2, 3 etc it refers to 50 Hz per count of drift. A drift of 1 or 2 positive or negative is common.
163708DE08078184903G51 +1 NN021EUB00023BCT@DZ@DY@Dc@Db@Dm@Dxj