Sizing AKT Remote IO

Introduction

AKD-PDMM controller/drive, AKD, AKD2G, and S700 drives, and PCMM standalone controller all contain hardware I/O that can be used in an application to interface to other control elements on the machine. Typically, to minimize overall system cost, IO point on these products are used first before the AKT Remote I/O is incorporated. AKT Remote I/O will also be used if a signal type not supported by Kollmorgen drives and controllers is needed in the application. This lesson reviews how to put together a remote AKT Remote I/O Block.

Parts to a AKT I/O Block

Every AKT I/O block must consist of the following:

• 1 Ethercat coupler: AKT-ECT-000-000
• 1 or more modules (slices)
• 1 End Module: AKT-EM-000-000

The AKT family

Consist of the following slices:

Complete model number list:

I/O Block Sizing

In the AKT Remote I/O system, many modules can be connected to one ECT coupler. In most applications, one Remote I/O block is all that is needed in the application. The following are guidelines to determine how many AKT-ECT-000-000 EtherCAT Coupler modules will be required.

Each remote IO configuration (block) starting with a AKT coupler (AKT-ECT-000-000 ) must not exceed any of the following limits:

• Slice Quantity Limitations The max number of slices connected to the coupler is 64, with 1 of them being an end module (AKTEM-000-000)
• Data Bus  Limitations The max number of data bytes the coupler can process to and from the EtherCAT network is 1024 bytes of input and 1024 bytes of output. The number of bytes a slice has is defined in the row "Bit width in the process image" in the specification sheet for each slice
• Power Limitations Each bus coupler module can provide:
  • Internal Bus (5 volt logic) power  -  1750 milliamp
  • 24V output power - 10 Amps. 

A Power Feed Module (AKT-PS-024-000 or AKT-PSF-024-000) can be added for an additional 10 Amps of 24V output power.

Other guidelines when putting together a remote I/O block

• An AKTEM-000-000 End Module is required to terminate each I/O block (AKT-ECT-000-000 coupler plus I/O slices)
• Thermocouple I/O modules ( AKTAN-200-000 and AKT-AN-400-000) do not pass through the 24 volt power. Therefore, in an IO rack they are typically placed to the right of the I/O slices and with the AKT-EM-000-000 End Module directly afterward.
• 24 Volt power module – AKTPSF-024-000 and AKT-PS-024-000 will provide a gateway to bring in additional 24 VDC power to the slices. The 24 VDC is applied to the slices mounted to the right of the slice
• Isolation Module – AKTIM-000-000 module interrupts the power contacts within a bus terminal block. This terminal enables operation with different voltages on the separated sides of the power contacts or to help facilitate electrical isolation for different sections of the machine. The data bus is looped through.
• For high-speed inputs, the AKTDNH-00x-000 Digital Input Modules offer very fast response but have less signal filtering (of high-frequency spikes).
• The Relay Output Module - AKT-DT-2RT-000 does not draw any 24 VDC bus current, since it's voltage is tied to an external source (an input connection directly into the slice)

Attached is a spreadsheet to help determine how many AKT-ECT-000-000 couplers are needed in an application. 

Example 1

The 4 axis application requires:

58 (24VDC) digital inputs:

• 7  (8 channel) input modules – 56 inputs
• 1 (4 channel) input slice  - use 2 of the 4 inputs

10 (24VDC) digital outputs:

• 1 (8 channel) output slices – 8 outputs
• 1 (4 channel) output slice  -  use 2 of the 4 outputs

18 ( 0 to 10 VDC) analog inputs

• 2 (8 channel) analog input slices – 16 inputs
• 1 (4 channel) analog input slice – use 2 of the 4 inputs

8  (0 to 10 VDC) analog outputs:

• 1 (8 channel) analog input slice – 8 outputs

2 Thermocouple inputs:

• 1 (2 channel) analog thermocouple input slice – 2 inputs

Conclusion: Only one coupler is needed. System totals for Slice Quantity, Data, and Power are within the limits for a coupler

Example 2

The 4 axis application requires: 58 (24VDC) digital inputs (3ms), 23 (24VDC) digital outputs, 13 ( analog 0 to 10 VDC) inputs, 12 Analog o to 10 volt analog outputs, and 2 thermocouple inputs,

58 (24VDC) digital inputs. Use:

• 7  (8 channel) input slices – 56 inputs
• 1 (4 channel) input slice  -  use 2 of the 4 inputs

23 (24VDC) digital outputs. Use:

• 2 (8 channel) output slices – 16 outputs
• 1 (8 channel) output slice – use 7 of the 8 outputs

18 (0 to 10 VDC) analog inputs. Use:

• 2 (8 channel) analog input slices – 16 inputs
• 1 (4 channel) analog input slice – use 2 of the 4  inputs

8 (0 to 10 volt) analog outputs. Use:

• 1 (8 channel) analog input slice – 8 outputs

2 Thermocouple inputs. Use:

• 1 (2 channel) analog thermocouple input slice – 2 inputs

Conclusion: The 24 VDC current draw is above the 10 amp limit indicating that two couplers are needed, with the modules or slices can be divided between the 2 couplers. System totals for Slice Quantity, Data, are within the limits for a coupler. The power limit of 10 amps is exceeded.

Alternative Conclusion 1: Add a AKT-PS-024-000 Power Feed module and only one AKT-ECT-000 will be needed

Alternative Conclusion 2:  12 of the 12.016 amps that make up the 24 DC current draw are 24 Digital Outputs (for 3 modules)  that allow for 0.5 amps/channel. Since only 23 channels are used and if it is verified that multiple channels require << 0.5 amps, the actual current demand may be < 10 amps allowing for the application to be done with one ECT coupler