Example 1

 integer*4 ext,data,q,status 
 call caopen("myserver",status) 
 call cdreg(ext,0,1,3,0)     ! point to register 
 call cfsa(0,ext,data,q) 
 if (q.ne.0) type *, "bad q at cnaf=1,3,0,0:",q 
 call cfsa(16,ext,1234,q)    ! write 1234 to register 
 call cfsa(0,ext,data,q) 
 if (data.ne.1234) then 
   type *, "bad compare: wrote 1234, read",data 
 endif