Project 06/2005 Danaher Motion
80 Rev E M-SS-005-03l
Sercos.CycleTime is used to either set or query the SERCOS
communications cycle time - rate of updating cyclic data (rate with which to
the desired phase of communication (see Cyclic vs. Non-Cyclic
Communication). This property is only set in SERCOS communication
phases 0, 1, and 2, transferred from the MC to drives during phase 2 and
becomes active in phase 3.
sercos.cycletime = 2000
? sercos.cycletime
Sercos.NumberAxes is used for querying the actual number of SERCOS
drives detected on the ring. This value is generated during communication
phase 1, when the SERCOS driver scans the ring for drives (or when the the
drive addresses are explicitly set)
? sercos.numberaxes
Sercos.Power is used to set or query the SERCOS transmission power. The
transmission power is governed by the SERCON interface chip and is set to
one of six levels. Setting the power level too high drives the fiber-optic
receiver into saturation and causes communication errors. This value should
not have to change unless a very long cable is being used (>10 meters).
Level 6 is the highest power.
Sercos.power = 3
? sercos.power
Sercos.Scan indicates to the SERCOS driver whether to scan the ring for
drives. If the property is set to a value greater than 0, the ring is scanned
during communication phase 1. The scan value indicates the highest drive
address for which to scan. For example, if the value is set to 5, the ring is
scanned for drives at addresses up to 5.
Sercos.scan = 0 ‘Do not scan the ring
Sercos.scan = 5 ‘Scan for drives up to address 5
Set SERCOS.PHASE to the desired phase of communication (see Enabling
and Communication Phases). Normally, the command stream outlined in the
procedure below is sufficient to bring up the ring. Because it takes time to
bring up the SERCOS ring, you may want to speed the process by changing
the phase only when it is at some phase other than 4.
Most IDNs have numeric values. After these IDNs are defined, you can read
their values with IDNVALUE. To do this, you must specify the drive address,
IDN, and the IDN element. For example, you can enter:
? IDNValue{5, 104, 7}
This lists the value of IDN 104, element 7, for the drive at address 5.
IDNVALUE is only executed in SERCOS communication phases 3 and 4 as
cyclic data, or in phases 2, 3, or 4 via the service channel (some restrictions
apply for writing to an IDN). For a complete listing of IDNs supported by the
SERVOSTAR drive, refer to the SERVOSTAR
®
MC Installation Manual.
IDNs have numeric values and you can write to most of them with the
WRITEIDNVALUE command. To do this, specify the drive address, IDN
and the value. For example, you can enter:
WriteIDNValue Drive = 5 IDN = 104 value=1
which sets the position loop gain (IDN 104) of drive 5 to 1.
WRITEIDNVALUE is executed only in SERCOS communication phases 2,
3 and 4.
