4-6
Using Trending to Aid Troubleshooting
The set-up parameters for the second trend will be identical to the first to
allow real time comparison between the data samples. The necessary set-up
parameter values for Trend File 2 are.
Parameter 900 “Trend Sign Val” = 4096 (per unit values)
Parameter 920 “Tr2 Opnd Param X” = 104 (test operand)
Parameter 921 “Tr2 Opnd Param Y” = 900 (constant operand)
Parameter 922 “Tr2 Operator” = .GT. (104 greater than 900)
Parameter 923 “Tr2 Sample Rate” = 0.004 (sample rate in sec)
Parameter 924 “Tr2 Post Samples” = 80 (# samples after trig)
Parameter 925 “Tr2 Mult Trigger” = OFF (single shot)
Parameter 926 “Tr2 Enable” = ON (enable trend)
When the Drive is accelerated to base speed the trend will trigger and the
data will be captured. Use the Bulletin 1300 programming terminal to
examine the data to determine which parameter exceeded the target
velocity.
Example 3
Occasionally, the Drive faults on VP-15 “External Overtemp”. The Drive’s
output at the time of the fault is unknown Trending will be used to
determine what the operating conditions of the Drive were when the fault
occurred. Motor velocity, torque command, and field flux effect the power
and subsequent heat These parameters will be monitored and output to the
Discrete Adapter analog output channels to examine the motor parameters
prior to the fault. The necessary links for this application are:
Parameter 50 “Trend 1 Input” to Parameter 106 “Velocity Fdbk”.
Parameter 51 “Trend 2 input” to Parameter 112 “Arm Current fdbk”.
Parameter 52 “Trend 3 Input” to Parameter 118 “Fld Current Fdbk”
Parameter 451 “Analog Out 1” to Parameter 001 “Trend 1 Output”
Parameter 452 “Analog Out 2” to Parameter 002 “Trend 2 Output”
Parameter 453 “Analog Out 3” to Parameter 003 “Trend 3 Output”
The sample period for the trend files will be programmed to 10 secs per data
point. The thermal time constant of most motors is quite large, the operating
parameters will be captured for 16 minutes prior to the occurrence of the
fault. The trigger will be programmed to occur when the fault occurs, the
fault will be reported in Parameter 101 “Drive Fault” bit 5. All 100 data
samples will be taken prior to the trigger. The necessary set-up parameter
values for Trend File 1 Are:
Parameter 904 “Trend Logic Val” = 00000000000100000 (bit sel)
Parameter 910 “Tr1 Opnd Param X” = 104 (test operand)
Parameter 911 “Tr1 Opnd Param Y” = 904 (constant operand)
Parameter 912 “Tr1 Operator” = .EQ. (operator for bit 5)
Parameter 913 “Tr1 Sample Rate” = 10 (sample rate in sec)
Parameter 914 “Tr1 Post Samples” = 0 (# samples after trig)
Parameter 915 “Tr1 Mult Trigger” = OFF (single shot)
Parameter 916 “Tr1 Enable” = ON (enable trend)
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