linuxcnc-ethercat

Wecon VD3E Servo Drives

The wecon driver supports Wecon’s VD3E single-axis EtherCAT servo drive.

Setup

In your XML file, you should have an entry somewhat like this:

<masters>
  <master idx="0" appTimePeriod="1000000" refClockSyncCycles="-1">
    <slave idx="0" type="VD3E" name="s"/>
  </master>
</masters>

See the CiA 402 documentation for additional details about how to configure CiA 402 devices in LinuxCNC. At a minimum, you will need to include the cia402 HAL component.

Note the refClockSyncCycles="-1"; see the distributed-clocks caveat below before changing it.

Devices

• VD3E single-axis EtherCAT servo drive, vendor ID 0x00000eff, product code 0x0d3e0001. CoE only (no FoE, no EoE).

The identity was read from live hardware and matches the vendor ESI “Wecon VD3E EtherCAT Servo V1.15.0.xml” (revision 0x00000073).

The related VD5 and VD5L drives share one product code (0x0d510001) and differ only by revision, so supporting them needs revision matching, not just another product code. Neither is supported yet.

Testing status

The VD3E has been tested on live hardware: driven to OP on a five-slave bus (three Inovance IS620N axes, the VD3E, and an Omron NX-ECC202 coupler), where it runs the spindle of a 3-axis mill in cyclic velocity mode. Object 0x6502 reads 0x3AD (pp, pv, tq, hm, csp, csv, cst), and position, velocity, torque and following-error feedback are live.

Caveats

• The drive assigns exactly one RxPDO and one TxPDO, and every mapping object holds at most 10 entries. Objects 0x1C12 and 0x1C13 each hold a single entry (defaulting to 0x1701 and 0x1B01); available mapping objects are 0x1600, 0x1701, 0x1702 for outputs and 0x1A00, 0x1B01 for inputs. A longer mapping is rejected and the slave never reaches OP. The driver keeps within these limits; keep them in mind if you enable more optional cia402 features or write your own PDO config for this drive.
• The bus cycle time should be 1 ms. The vendor manual recommends 1 ms and does not guarantee stability below it.
• Objects 0x608F (position encoder resolution) and 0x6092 (feed constant) do not exist on this drive. The encoder resolution is 2^23 counts per revolution (23-bit absolute encoder); the manufacturer object U0-52 = 0x201E:0x34 reports the number of encoder BITS (resolution = 1 << bits), as a UINT16. Feed constant has no substitute: only the electronic gear 0x6091 exists, defaulting to 1:1, so out of the box 0x6064 carries raw encoder counts and mm scaling is the master’s job.
• Drive temperature is not exposed in any object. DC-bus voltage is U0-31 = 0x201E:0x1F, a UINT16; with mains applied it read 3157, which puts the unit at 0.1 V (315.7 V, the expected rectified 220 V). That scale is inferred, not stated by the manual — check it against a meter before showing volts to an operator.
• 0x603F carries a vendor code, not a CiA 402 one. Read as DECIMAL, its value is the digits of the code on the drive’s own display: 34 is Er.34 (motor overload), 82 is A-82. Formatting the same value as hex points the operator at a different fault entirely. The full table of codes is chapter 11.2 of the vendor manual.
• Keep the firmware and the ESI in step. The standard 0x100A (“Manufacturer Software version”) returns the firmware as a string — V1.15 here, the latest at the time of writing — and the ESI states the firmware it describes. A drive older than the ESI needs the vendor’s firmware upgrade tool.
• SDO Info works on this drive. The whole object dictionary can be walked with ethercat sdos, and the manufacturer groups are named there (0x201E = “U0 Group monitor”, 0x2020 = “U2 Group Monitor”, 0x2000..0x200D = the P0..P13 parameter groups). Useful when you need a vendor object and only have the manual’s Pxx-yy / Uxx-yy numbering.
• SDO writes must not use complete access. The drive NAKs complete-access SDO writes; this is per vendor, not per bus.
• Distributed clocks converge only with master-to-slaves distribution (refClockSyncCycles="-1"); with a positive value the clocks did not converge at all. The driver enables DC by default (assignActivate 0x300, SYNC0 at the application cycle time, shifted by half the cycle). The half-cycle SYNC0 shift is the manual’s recommendation — advance the PDI by 50% of the SYNC0 period — and their fault E.101 (“ECAT sync error”) names an unreasonable master SYNC Shift Time as its first cause; measured, the shift buys much faster startup convergence. Override with a <dcConf> element if needed.
• Touch probe is not enabled. The probe objects (0x60B8..0x60BD) exist, and 0x60B8 even sits in the factory RxPDO, but the driver does not map them: they have not been run on hardware yet, and a wrong mapping costs the OP transition.

Configuration

There are no Wecon-specific <modParam> options; the standard cia402 modParams apply. The driver enables the following cia402 features on top of the base set: opmode selection, CSP, CSV, CST, target torque, actual torque, actual following error, and the error code (0x603F ships in the factory TxPDO, so exporting it costs nothing).

To override the default distributed-clock settings, use a <dcConf> element on the slave as usual.

Pins

The driver exports the standard cia402 pin set, prefixed with lcec.<master>.<slave-name>.srv-, for example:

• srv-cia-controlword, srv-cia-statusword
• srv-opmode, srv-opmode-display
• srv-actual-position, srv-actual-velocity, srv-actual-torque
• srv-target-position, srv-target-velocity, srv-target-torque
• srv-actual-following-error, srv-error-code
• srv-supported-modes, srv-supports-mode-{pp,pv,tq,hm,csp,csv,cst}

See the CiA 402 documentation for the full list and semantics.

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