STARTUP / TROUBLESHOOTING
5-11
Hardware and Installation User Manual
5.2.3.4
Status Words Seven to Nine (STW07–STW09)
STW07 gives the absolute address of the first error encountered while
attempting to program the EPROM/EEPROM. The value given is the memory
address of the EPROM/EEPROM memory.
STW08 shows the checksum calculated from the RLL program stored in the
EPROM/EEPROM. The checksum is a numerical calculation based on your
RLL program only. When you copy a program to several EPROM/EEPROMs,
you can check STW08 for every EPROM/EEPROM to verify that the
information contained in each is identical.
NOTE
Identical RLL programs and identical I/O configurations
programmed in different machines may yield different
checksums due to internal storage differences.
STW09 shows the checksum generated from the EPROM/EEPROM. The
checksum is a numerical calculation based on all data stored in the
EPROM/EEPROM, including your RLL program and information contained in
the I/O configuration memory. When you copy a program to several
EPROM/EEPROMs, you can check STW09 for every EPROM/EEPROM to
verify that the information contained in each is identical.
5.2.3.5
Status Word Ten (STW10)
STW10, shown in Figure 5-5, provides the PLC scan time in binary code. If you
display the integer value of the word, the program scan time is given in
milliseconds. The PLC updates the word each scan.
STW10
Bit
1
2
3
4
5
6
7
8
9 10
11 12 13 14 15 16
0
0
0
0
0
0
0
0
1
0
0
0
0
0
0
0
= 8 ms P/C
scan time
MSB
LSB
Figure 5-5
Format of Status Word Ten (STW10)
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