An illustrative run making a spectrum and its response matrix.

First we read the data in...
genji.gsfc.nasa.gov> xselect
 
                         **  XSELECT V2.0   **
 
> Enter session name >[xsel]   
 
 Notes: XSELECT set up for      ASCA
 Time keyword is TIME       in units of s
 Default timing binsize =   16.000
 
xsel:ASCA > read e
> Enter the Event file dir >[./] 
> Enter Event file list >[] s3good.evt
Got new mission: AXAF
> Reset the mission ? >[yes] 
 
 Notes: XSELECT set up for      AXAF
 Time keyword is TIME       in units of s
 Default timing binsize =   16.000
 
 
Setting...
 Image  keywords   = X          Y           with binning =    4
 WMAP   keywords   = CHIPX      CHIPY       with binning =   32
 Energy keywords   = PHA                    with binning =    1
 
 
Getting Min and Max for Energy Column...
Got min and max for PHA:     0  36855
 
Could not get minimum time resolution of the data read
Number of files read in:            1
 
******************** Observation Catalogue ********************
 
Data Directory is: /local/genji/data3/kaa/SSA13/S3/
HK Directory is: /local/genji/data3/kaa/SSA13/S3/
 
 
        OBJECT      DATE-OBS    LIVETIME DETNAM      READMODE    FIRSTROW    NROWS
      1 S-Z CLUSTER 1999-12-03  0.97E+05 ACIS-23678  TIMED       NOT_FOUND   NOT_FOUND

Switch to extracting in PI space...

xsel:AXAF-ACIS-FAINT > set phaname PI
 
Getting Min and Max for Energy Column...
Got min and max for PI:     0   1024
 
Define the region filter, extract the spectrum and save it...

xsel:AXAF-ACIS-FAINT > filter reg src10.reg
xsel:AXAF-ACIS-FAINT > extr spec
extractor v3.79  21 Jun 2000
 Getting FITS WCS Keywords
 Doing file: /local/genji/data3/kaa/SSA13/S3/s3good.evt
100% completed
          Total      Good    Bad: Region      Time     Phase       Cut
         254298       265         254033         0         0         0
===============================================================================
   Grand Total      Good   Bad:  Region      Time     Phase       Cut
        254298       265         254033         0         0         0
   in  96928.     seconds
 Spectrum         has      265 counts for 2.7340E-03 counts/sec
 ... written the PHA data Extension
xsel:AXAF-ACIS-FAINT > save spec testit.sp group=no
Truncated the spectrum to      1 -   1024
Wrote spectrum to testit.sp

Note that xselect truncates the spectrum to 1-1024 (it is actually 0-1024 in the files but PI=0 is invalid). Now leave xselect and run acismakermf...

xsel:AXAF-ACIS-FAINT > quit
> Save this session? >[no] 
genji.gsfc.nasa.gov> acismakermf testit.sp s3 testit.rmf

Observation performed on 12/03/1999
Detector temperature is -110 C

acisrmf infile=testit.sp rmfdir=/chandra/calib_data/acis/s3/rmf/00may/ ccdtemp=-110 outfile=temp.lst fefoption=no
acisrmf v1.3    21 Jun 2000

addrmf list="@temp.lst" rmffile=testit.rmf
ADDRMF vers 1.15  17 March 2000.
Summing ...
 3.434E-01 * /chandra/calib_data/acis/s3/rmf/00may//bi7c0_110/ccd7_c0.0.21.32.pi.rmf
 2.226E-01 * /chandra/calib_data/acis/s3/rmf/00may//bi7c0_110/ccd7_c0.1.21.32.pi.rmf
 2.792E-01 * /chandra/calib_data/acis/s3/rmf/00may//bi7c0_110/ccd7_c0.0.22.32.pi.rmf
 1.547E-01 * /chandra/calib_data/acis/s3/rmf/00may//bi7c0_110/ccd7_c0.1.22.32.pi.rmf
 RMF #    1 : /chandra/calib_data/a      0.34
              CXC        ACIS       NONE       NONE       PI
 RMF #    2 : /chandra/calib_data/a      0.22
              CXC        ACIS       NONE       NONE       PI
 RMF #    3 : /chandra/calib_data/a      0.28
              CXC        ACIS       NONE       NONE       PI
 RMF #    4 : /chandra/calib_data/a      0.15
              CXC        ACIS       NONE       NONE       PI
 ... using rdrmf4 1.3.2
 ... read all the keywords
 ... reading the data
 ... successfully read RSP_MATRIX data
 ... using rdrmf4 1.3.2
 ... read all the keywords
 ... reading the data
 ... successfully read RSP_MATRIX data
 ... using rdrmf4 1.3.2
 ... read all the keywords
 ... reading the data
 ... successfully read RSP_MATRIX data
 ... using rdrmf4 1.3.2
 ... read all the keywords
 ... reading the data
 ... successfully read RSP_MATRIX data
 ...  using wtrmf4 1.4.0
 ... new extension created
 ...  Max # elements in F_CHAN & N_CHAN arrays =        2
 ...  Max # elements in MATRIX array =       62
 ... Using Variable length array for MATRIX column
 ... written the extension header keywords
 ... written the OGIP required keywords
 ... written the history keywords
 ... written the comment keywords
 ... defined the data structure
 ... successfully written RSP_MATRIX data