Switching over parameter sets

 Valid for S300, S700

General

For the use of servo amplifiers it often happens, that the amplifier parameters must be changed during operation.

Although the S300 and S700 offer the possibility of executing an arbitrary command consequence to switch over ASCII parameters with the help of a digital entrance (for example input 1: IN1MODE = 30), but that process has certain disadvantages:

1. The processing of ASCII commands has a relatively low priority so that the switch over can take 10 ... 500  ms
2. Switching over several parameters is sequentiel, that means some parameters are switched over earlier than others. This can lead to unintended situations.

To eliminate these disadvantages, a function for switching over parameter sets has been implemented from firmware 2.11.

Realization

Switching over parameter sets is realized with a pointer, which always points to one of the two parameter structures (parameter set 1: default or parameter set 2: shadow parameters). While switching the pointer between these two structures all parameters that are defined in the structures are switched over in parallel. Because the parameters are already converted in the structures, it is avoided that undefined conditions occur.

The parameters of the second parameter set are defined similarly to the major parameter set by ASCII commands. To define the second parameter set, the sequence "_X" must be added to the ASCII command.

Example:
The command "GV" is used to define the gain of the velocity controller. To change this parameter in the second parameter set the command "GV_X" must be used.

To save memory in the amplifier, only those parameters are stored in the second set, which differ from the first parameter set. If no parameter is preset for the second set, thes econd set is initialised automatically identical to the first set. The user must therefore only define the required parameters for the second set, not all parameters.

The automatic initializing of the second parameters set always requires an update of the set, if a parameter of the first set has been changed. This could result in a reset of special second set parameters. To avoid this, the parameterizing of the second set must always been done after initializing the first set.

As soon as PAR_X gets a different value than PAR,this parameter is saved in the serial EEPROM. The value of PAR_X now appears in the DUMP list at the end of the parameter section.

All parameters that can be used for this functionality can be listed combined with their values by the command PARDUMP.

Switch over active parameters

Switching over the parameter sets can be done via a digital input or triggered by an internal function.

1. Switch over via a digital input with INxMODE=57 (for example input 1: IN1MODE = 57).
   Only one digital input may be set with this function (otherwise warning n24 – Parameter Fault).
   If a digital input is configured with INxMODE=57, no functional triggering of the parameter set switch over is possible, that means PARCNFG must be set to 0 (otherwise warning n24 – Parameter Fault).
   Level of the digital input defines the active parameter set::
   - Low   : first parameter set (major set)
   - High  : second parameter set (shadow set)
2. Automatic switch over depending on status of the servo amplifier
   With the bit variable PARCNFG internal functions can be selected, which activate the second parameter set automatically:
   PARCNFG = 0x0000    no automatical switch over
   PARCNFG = 0x0001    second parameter set active during Wake and Shake
   PARCNFG = 0x0002    second parameter set active during motion task (homing / jog mode).

To save memory not all parameters have been implemented in the second parameter set.

Usable parameters

These parameters can be used for switch over (2006-06-22):

GP,GPFFT,GPFFV,GV,GVFR,GVTN,
KC,KTN,
MICONT,MIPEAK,MJ,MKT,ML,MLGC,MLGD,MLGP,MLGQ,MPOLES,MRS,MTIME

With PARDUMP you can create a current list of usable parameters.

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