DataQ hardware is setup as so:

   Channel    Data_description

      1       East Tac (after /5 from Tacs).
      2       West Tac
      3       HA Vel, roughly:  (East_tac+West_tac)/-2)
      4       Pmac East Out
      5       SB East Out
      6       PMAC West Out
      7       SB West Out

      8       North Tac
      9       South Tac
     10       Dec Vel, roughly:  (North_tac+South_tac)/-2)
     11       Pmac North Out
     12       SB North Out
     13       PMAC South Out
     14       SB South Out



The TAC output is 12 volt per radian on motor staff.
We measure the voltage after 144 gear ratio, and /5 circuit
in SB. Conversion to as/s is Volts * V2AS, V2AS is 596.831

1. to plot all tac data to a as/s scale:

   plot 'data.txt' using ($1*596.831) 
   replot 'data.txt' using ($2*596.831) 
   replot 'data.txt' using ($3*-596.831)