The RF measurement situation is a little tricky because of the differences
between the unit structure in the copper and in the superconducting RF.


With the copper RF there are:

4 cells to one cavity,
5 cavities to one module,
4 modules to one unit,
one unit is driven by two klystrons.

                 Power Supply
                     |
                     |     
                  K1    K2
                     /\
                    /  \        
                   /    \ 
                  /      \
                 /        \
                /\        /\
               /  \      /  \
              M1  M2    M3   M4
              |    |    |    |
             4C   4C   4C    4C



*--------------------------------------------------*


With the superconducting RF there are:

4 cavities to one module,
one klystron drives 2 modules (half unit),
one power supply drives both klystrons.


                     PS
                    /  \
                   /    \ 
                  K1    K2
                 /        \
                /          \
               /\          /\
              /  \        /  \
             M1  M2      M3   M4
             |    |      |    |
            4C   4C     4C    4C

NB For measurements we treat each 1/2 unit separately. 
So for unit LRF_233 we have LRF_233_1 (driven by K1) and LRF_233_2 (driven by K2).


* RF Unit logging Parameters                     

 * The parameters are interpreted slightly differently according 
to whether the unit is copper or superconducting.

M_RF_UNIT_DATA
(
act_hw_name char(20),  /* Actual Hardware Name - eg LRF_671 (Cu), LRF_233_1 (SC - 1/2 unit) */

timestamp date,

htr char(12),     /* Klystron Heater */

cu_htr2 char(12), /* Heater K2 - Copper ONLY */

mcb  char(12),    /* HV main circuit breaker */

ps   number,      /* Power Supply o/p in kV */

vcl  char(12),    /* Klystron Volt. loop ( Cu - both klystrons)  */

dcl  char(12),    /* differential loop  Copper ONLY  */

kfor number,      /* Fwd power Klystron in kW */

kref number,      /* Refl power in kW. SC - per Klystron. CU - sum of K1 + K2 */

cu_k2for number,  /* Fwd power K2 in kW - Copper ONLY */

mv    number,     /* RF voltage in MV */

dsum  number,     /* Cav detector sum in % */

cavf  number,     /* Tot fwd power in kW */

cavr  number,     /* Tot refl power in kW */

);