Rockwell Automation 1771-VHSC , D17716.5.74 Very High S - Manual (Page 52)

6–2 Troubleshooting
The VHSC module returns diagnostics in word 1 of the block
transfer read (BTR) to the processor. These codes are identified
below.
Diagnostics Reported in Word 1 of BTR
Word Bit Indication
1 Bit 00
PowerĆup bit indicates whether a successful BTW with valid data has
occurred since powerĆup, or since last switched from Program to Run mode.
Bit 0 = 0 Ć Successful BTW
Bit 0 = 1 Ć BTW has not occurred
Bits 01Ć03 Not used
Bits 04Ć07 New data bits. Bit 04 corresponds to counter 0, bit 05 to counter 1, etc.
Bits 08Ć15
Diagnostic byte. This byte is always in BCD format. This byte indicates which
word (1Ć64) in the BTW file that was incorrect, or one of the following error
codes. The codes are as follows:
Code
87 Preset or reset illegal for counter 0 with frequency mode
88 Preset or reset illegal for counter 1 with frequency mode
89 Preset or reset illegal for counter 2 with frequency mode
90 Preset or reset illegal for counter 3 with frequency mode
91 Store count illegal for counter 0 with frequency mode
92 Store count illegal for counter 1 with frequency mode
93 Store count illegal for counter 2 with frequency mode
94 Store count illegal for counter 3 with frequency mode
95 Preset greater than rollover for counter 0
96 Preset greater than rollover for counter 1
97 Preset greater than rollover for counter 2
98 Preset greater than rollover for counter 3
99
BTW length invalid Ć length not equal to 0, 1, 2, 4, 12, 20, 24, 29,
34, 39, 44, 49, 54, 59, 64.
In this chapter, you learned how to interpret the module indicators,
and the meanimg of the error codes returned by the module.
Diagnostic Codes
Returned by the Module
Chapter Summary