MFC rev. 1.50:
MFC rev. 1.50:

  Fix calculation of descriptor tag checksums. According to ECMA-167, Part 4,
  7.2.3, bytes 0-3 and 5-15 are used to calculate the checksum of a descriptor
  tag.

Approved by:	emax (mentor)

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase