Danaher Motion
06/2005
Project
M-SS-005-03 Rev
E
81
Some IDNs have alpha-numeric string values. After these IDNs are defined,
you can read the string values with
READIDNSTRING
. Specify the drive
address, IDN, and IDN element. For example, you can enter:
? IDNString(5, 104, 7)
IDNSTRING
is used only in SERCOS communication phases 2, 3 and 4.
Some IDNs have alpha-numeric string values. After these IDNs are defined,
you can write new string values to most of them with
WRITEIDNSTRING
.
Specify the drive address, IDN and the value. For example, you can enter:
WriteIDNString Drive = 5 IDN = 104 Element = 7
String = IDN String
WRITEIDNSTRING
is executed only in SERCOS communication phases 2,
3 and 4.
IDNState
returns the state of a specified procedure command from a
specified drive. It is used when executing a procedure command to
determine progress of that procedure’s execution. Common procedures are
99 (clear faults) and 148 (drive-controlled homing).For example, you can
enter:
‘Check how procedure terminated
If IdnState(a1.dadd, 99) <> 3 Then
Print “Reset Faults procedure failed”
End If
For more information about states of this property, refer to the
SERVOSTAR
®
MC Reference Manual.
Use
MOTIONLINK
to configure and operate the SERVO
STAR
drive. The
parameters are stored in the drive, but not in the controller. So, if you need to
replace a drive in the field, you must reconfigure that drive with
MOTIONLINK
.
One benefit of SERCOS is that it allows you to download all drive
parameters via the SERCOS link each time you power up. If you need to
replace a SERVO
STAR
drive, you do not need to configure it with
MOTIONLINK
. This is a significant advantage when maintenance people
unfamiliar with the design of the system do drive replacement. For this
reason, Danaher Motion recommends that you configure your systems to
download all parameters on power up. BASIC Moves provides a utility that
reads all pertinent IDNs after the unit is configured and the ring is up and
stores them in a task you automatically download each power up.
3. 13
L
OOPS
The SERVO
STAR
system supports three main loop types:
Standard position loop
Dual-feedback position loop
Velocity loop
The MC sends position and velocity commands each SERCOS update cycle.
The operation of the MC is hardly affected by the loop selection because the
loop selection is made in the drive.