Simcenter Testing Solutions Simcenter SCADAS: Main-Secondary Daisychain

Simcenter SCADAS Simcenter Testlab



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Need to test more channels than contained in a single SCADAS data acquisition unit? No problem!

Separate Simcenter SCADAS hardware data acquisition units can be daisy chained together as shown in Figure 1:
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Figure 1: Multiple Simcenter SCADAS units can be daisy chained together via fiber optic cable cables (orange) to act as a single data acquisition unit.

The channels of the separate SCADAS units are treated as a single unit in the Simcenter Testlab software:
  • Software User Interface: A single list of all channels from the separate hardware units is shown in the Simcenter Testlab software interface.
  • Data File: All channels are simultaneously sampled at the same rates and stored into a single file.  

1.    Required Hardware
2.    Setup
3.    Operation
4.    Shut Down

 1. Required Hardware

Any Simcenter SCADAS Mobile and SCADAS Recorder used to daisy chain the units together must be equipped with a Main-Secondary card as shown in Figure 2:
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Figure 2: To daisychain SCADAS hardware units together, a Main-Secondary card is used (outlined in green, upper right of the frame).
The card is in the upper right corner of the Simcenter SCADAS frame. The card is not a standard feature and must be purchased separately with most SCADAS units (see below). 

The card is equipped with two fiber-optic ports.  One fiber optic cable is provided with any main-secondary card to connect SCADAS units together (Figure 3).
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Figure 3: Fiber optic cable to connect SCADAS hardware.

SCADAS frames can be ordered as Main units (normal) and Secondary units:
  • Main: A main SCADAS unit has a XSI/SYSCON controller card.  Most SCADAS units are ordered in this manner. A main SCADAS unit does not come with a Main-Secondary card [Product code: SCM-MS] by default.  Must be ordered separately.  The Main-Secondary card is shipped with one fiber-optic cable by default.
  • Secondary: A secondary SCADAS unit does not include a XSI/SYSCON controller card.  This gives one additional data acquisition card slot (example: a 6 slot SCM06S) versus a corresponding main SCADAS unit (example 5 slot SCM2E05).  A secondary frame does include a Main-Secondary card [Product code: SCM-MS] and one fiber-optic cable.
The Main-Secondary card will work in any sized Simcenter SCADAS Mobile or Simcenter SCADAS Recorder except the SCADAS 01 series (which has only one useable slot for data acquisition cards).

2. Setup

The Main-Secondary switches of the SCADAS units should be set as follows:
  • Main SCADAS: In the upper right corner of the primary SCADAS set the switch on M for Main. The ethernet connection of the primary SCADAS will be used to connect to the computer used for data collection.
  • Secondary SCADAS: The switch should be set to S on any secondary SCADAS.  These units will not be connected via ethernet to the host computer.  Secondary units will only be connected to the main SCADAS or other secondary SCADAS units.

The switch positions are shown in Figure 4.
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Figure 4: Positions for Main-Secondary switches.

To daisy chain two SCADAS hardware units together, the fiber optic cables are installed as shown in Figure 5:
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Figure 5: Connect the PREVIOUS of the main SCADAS hardware to the NEXT of the secondary SCADAS and vice versa.

The fiber optic cables are installed to form a “loop” between the main and secondary SCADAS hardware units.  The PREVIOUS connector of one SCADAS unit is connected to the NEXT of the other SCADAS unit.

The loop is particularly important if more than one secondary SCADAS is being used as shown in Figure 6.
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Figure 6: Multiple SCADAS units require that the last secondary SCADAS be connected to the main SCADAS.
Here a loop is completed by connecting the last secondary SCADAS (NEXT port) to the main SCADAS (PREVIOUS port).

3. Operation

The SCADAS unit being used in a main-secondary arrangement must be powered up in a specific sequence as shown in Figure 7.
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Figure 7: Secondary units need to be powered up before the main SCADAS unit.

The secondary SCADAS must be powered up before the main SCADAS is powered up. If the power is not done in this sequence, the channels on the secondary SCADAS will not be useable (nor shown) in the Simcenter Testlab software interface.

Each SCADAS requires a separate power cord.

The controller card (with ethernet interface) of secondary SCADAS will not function (Figure 8).
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Figure 8: Controller card on secondary SCADAS will not function.

The controller cards ethernet, CAN bus, tachometer inputs, and sources will not function on the secondary unit.  This makes the SCADAS slot that the controller occupies available for a data acquisition card.  This way, more even more channels can be used in the main-secondary arrangement.

Data can be acquired using the Simcenter Testlab software.  All data from the separate SCADAS units will be stored in a single file containing all channels (Figure 9).  
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Figure 9: Final configuration for acquiring data in main-secondary operation.

The data across all channels stored in the resulting file is completely synchronized.

 4. Shut Down

After acquiring data, a few things to remember:
  • Turn the switch on the secondary back to M.  The next person who uses the SCADAS will not be able to take data because the ethernet is disabled (assuming they use it as a main unit).
  • Don’t forget to turn off the power of each unit separately.  This can be overlooked (especially for the secondary) and the battery will drain while in storage.

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KB Article ID# KB000069312_EN_US



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