Rockwell Automation 23P PowerFlex Digital DC Drive - Manual (Page 312)

312 Rockwell Automation Publication 20P-UM001K-EN-P - July 2014
Appendix C Application Notes
Linking Parameters Via the Scale Block Parameters
Most parameter values are entered directly by the user. However, certain
parameters can be “linked” by using the Scale Block parameters so the value of
one parameter becomes the value of another.
For example, the value of an analog input 1, parameter 70 [Anlg In1 Sel], can be
linked to parameter 660 [Accel Time 1]. Follow these steps to link parameters.
1. Set parameter 70 [Anlg In1 Sel] to 12 “UserDefined0”.
2. Set parameter 484 [Scale1 Input] to “503” (the parameter number of
[UserDefined0]).
3. Set parameter 485 [Scale1 Output] to “660” (the parameter number of
[Accel Time 1]).
In this way, rather than entering an acceleration time directly (via HIM), the link
allows the value to change by varying the analog signal. This can provide
additional flexibility for certain applications. Test this functionality for the
desired response before applying to an application.
SCR Diagnostic Tests Two SCR diagnostic functions are available; (1) Open SCR, and (2) Shorted
SCR. Each test is run to identify which SCR or SCR pair has failed, including
multiple SCR failures. However, if the drive cannot determine the specific
shorted SCR or SCR pair, a shorted SCR (b15) is indicated in Par 214
[SCR Diag Status] and bits 0…11 remain off (0). Each diagnostic function can be
enabled/disabled independently (default is disabled) via parameter 213 [SCR
Diag Test En] and each operate after the drive is started. Typically, enable the
SCR diagnostic functions when a problem is suspected.
When enabled, the Shorted SCR test pulses each SCR/pair immediately after a
Start command (and the contactor is closed). This results in a short delay before
controlling the motor. If a shorted SCR is detected, a non-configurable fault is
generated.
The Open SCR test monitors voltage and/or current and uses adjustable
parameters (215 [OpenSCR WarnLvl], 217 [OpenSCR Threshold, and 218
OpenSCR Trip Lvl]] to determine when and if to initiate a fault or alarm
(configurable via parameter 216 [OpenSCR Flt Cfg]).
Parameter 214 [SCR Diag Status] shows which SCR(s) were detected as failed
(open or shorted).