HEDA: High Efficiency Data Access
- Real-time data transfer
- High-stage axis synchronization
- Fixed transfer rate of 10MBit/s
- Jitter < 300ns (Bus) which results in a high synchronicity
- Peer-to-Peer communication
- Maximum cable length 50m (greater lengths on request)
- 1 Master / 31 Slave: Individual HEDA axis address in the range between /1...32
fixed cycle time of 0.5ms
- Synchronization of the scanning grid of the digital control loops and of the setpoint generation
- Cyclic data exchange
- Acyclic data exchange of time-uncritical values
On the Compax3, it is available on I12T11, T30 and T40 units with the Option M10 or M11. The C3 I10T10 or I11T11 with HEDA bus is not available.
The Master C3 has to be either a T30 or T40. (An I12T11 cannot be a HEDA master.) The slave C3 can be a T30 or T40 axis (such as doing a different CAM profiles with the same master clock signal), or a I12T11 (where multiple C3s would be doing the same CAM or move profile as the Master C3).
The HEDA connectors does not give Ethernet TCP/IP connectivity to the Compax3. (For this, use the Ethernet/Powerlink I30 option which has a TCP/IP connection available in addition to the Ethernet Powerlink).
HEDA is a closed protocol and cannot be used for HMI or PC communication. This is a separate option from the fieldbus options (I20 ProfiBus, I21 CanOpen, I22 DeviceNet, I30 Ethernet/Powerlink, I31 EtherCAT, I32 ProfiNet). These fieldbus options are still available for external PLC control to the Compax3s and multi-axis synchronization with HEDA.
Note as there is no feedback from the slave C3 to the master C3, this is not recommended for applications where both motors are attached to the same physical load (such as a gantry). For gantry applications, the better choice is to use an ACR9000 controller which has Gantry Lock and the two Compax3 drives as amplifiers. This gives better control and gives multi-axis programmability flexibility.
The BUS07/01 HEDA bus terminators include 2 terminators and one is placed on the Master and the second on the last Slave. The SSK28/ cable can be used to interconnect the HEDA Compax3s. This is the same as an ethernet patch cable (568A).
Click here for: Simple HEDA example (.zip)
This sample shows a T40 configured as a HEDA Master with a simple CAM profile. The slave is a I12T11M11.
The slave is externally controlled via I/O like the I12T11M12 but one of it's moves is set as a Gearing move. After enabling the drive and setting the No Stop bits and homing if necessary, set the Address bit M.I0 and then give it a M.I5 Start (edge triggered). This will then gear to the HEDA master. Multiple drives can be configured in the same manner, changing the HEDA address in the Signal Source > Gearing configuration:
Note that the HEDA Master is set within the Communications setting. This is already set within the examples:
Click here for: Advanced HEDA Example (.zip)
4-axis Compax3 HEDA system, all T40 units
This shows infeed axis with CAM (forwards and backwards movement) profile and the second axis a rotary knife with its own CAM profile synchronized to the commanded position of the first axis Master.
The third and fourth axes synchronize to the rotary knife's actual position and has slip correction. All have different numerators and denominators, showing how different mechanics can be synchronized.
For further description, see pdf within above zip file