Configuring UI/O High-Speed Channels

Each of the Universal I/O module's two RS-422 channels are independently configurable as Quadrature or SSI. These channels must be configured before being used for such tasks as assigning to axis inputs. To configure the channels, open the UI/O properties:

In the Project Pane, expand the Modules folder.
Double-click the desired UI/O module, then choose the Quad/SSI page.
Each channel can be configured to operate in one of the modes listed in the table below. See the sections below for instructions on configuring the channels for specific uses.

Quadrature Input	Is used by assigning to a control or reference axis. +/-A and +/-B differential inputs with wire break detection. One I/O point per channel (R0 for channel 0 or R1 for channel 1) can be used as a reference or home input for high-speed count latching. Filtering on the R0/R1 input for use in high-speed latching is configurable via an axis parameter. Termination on the A and B inputs can be enabled/disabled via an axis parameter.
SSI Axis Input	Is used by assigning to a control or reference axis. The following items can be configured via axis parameters: SSI Clock Mode: Standard (Clock is output) or Monitor (Clock is input) Wire Delay Compensation: Selects the amount to delay sampling Data with respect to Clock. A wizard is provided to calculate the proper value. SSI Input Termination: Enable/disable termination on the Data input (and Clock input for Monitor mode) SSI Clock Rate: 250 kHz, 500 kHz, or 971 kHz SSI Data Format: Gray code or binary SSI Data Bits: 8-32
SSI Register Input	Result is placed in any selected variable. This type of input cannot be assigned to an axis. The same configuration options as SSI Axis Input are provided for this mode, but are located in the Quad/SSI setup page for the module instead of in axis parameters.
SSI Output	Outputs the contents of a selectable register over the SSI +/-Data lines. Also, channel 1 has the option of automatically echoing the data coming in on channel 0 (if configured as an SSI Axis/Register Input) in which case a register is not selected. This is useful in cases where the user wants to share the SSI feedback with other devices. The following items can be configured through the Quad/SSI setup page: SSI Output Mode: Master (Clock is output) or Slave (Clock is input) SSI Termination (Slave mode only): Enable/disable termination on the Clock input SSI Clock Rate: 250 kHz, 500 kHz, or 971 kHz SSI Data Format: Gray code or binary SSI Data Bits: 8-32

Configure Channel as a Quadrature Axis Input

For each channel that will be used as an input to an axis, do the following:

Choose Quadrature Input, then click OK.
Wire the quadrature input as described in the RMC150 UI/O Wiring topic.
Assign the input to an axis as described in the Defining Axes topic.
In the Axis Parameters Pane, set the following axis parameters:
- Input Termination to apply termination. Termination should always be used. If the high-speed channel inputs are daisy-chained, apply termination only to the last input in the chain. See RMC150 UI/O Wiring topic for details.
- If the axis will use the Reg input for registration or homing, uncheck Filter Reg Input if you need a faster response and are not concerned about electrical noise.
Scale the axis feedback as described in the Quadrature Scaling topic.

Configure Channel as an SSI Axis Input

For each channel that will be used as an input to an axis, do the following:

Choose SSI Axis Input, then click OK.
Wire the SSI input as described in the RMC150 UI/O Wiring topic.
Assign the input to an axis as described in the Defining Axes topic.
In the Axis Parameters Pane, set the following axis parameters:
- SSI Data Bits
- SSI Format
- SSI Termination to apply termination. Termination should always be used. If the high-speed channel inputs are daisy-chained, apply termination only to the last input in the chain. See RMC150 UI/O Wiring topic for details.
- Set the SSI Clock Mode to Standard
- SSI Clock Rate, if necessary. The default value is usually fine.
- SSI Wire Delay, if necessary, as described in the SSI Wire Delay topic.
- SSI Overflow Mode, if necessary. The default value is usually fine.
Scale the axis feedback as described in the SSI Scaling topic.

Configure Daisy-Chained SSI Devices to Multiple UI/O Modules

Daisy-chaining refers to wiring an SSI device to multiple UI/O modules. When wiring a daisy-chained SSI system, the SSI master (the UI/O) should be on one end of the daisy chain with the SSI device on the other end, and any monitoring UI/O modules in the middle of the daisy chain. The wiring must be done in a sequential fashion, that is, the wiring goes from the SSI device to the first UI/O, then from that UI/O to the next UI/O, etc. Apply termination only to the SSI master. See RMC150 UI/O Wiring for more details.

Configure a channel on the master UI/O as an SSI Axis Input as described in the Axis Input section above. Use the SSI Termination parameter to apply termination.
For the remaining monitoring UI/O modules:
1. Configure a channel as SSI Axis Input as described in the Axis Input section above, but set the SSI Clock Mode parameter to Monitor and do not apply termination.

Using SSI Output Mode

The SSI Output mode can be used to configure the SSI channel for the following:

SSI Device
The SSI channel behaves an encoder. This can be used to transfer data to a controller that has a standard SSI input. The remote controller sends a clock signal to the SSI channel, and the SSI channel returns the data.

In the Mode box, choose SSI Output.
Choose Output the Contents of the following Register.
Set the SSI Output Mode to Slave.
Set the remaining parameters as required.

SSI with Clock Output and Data Output
This is designed for connection of this channel to an SSI Monitor channel (with both clock and slave as inputs).

In the Mode box, choose SSI Output.
Choose Output the Contents of the following Register.
Set the SSI Output Mode to Master.
Set the remaining parameters as required.

SSI Echo
Channel 1 is an SSI device and outputs the same data that Channel 0 received.

In the Mode box, choose SSI Output.
Choose Automatically retransmit SSI Input 0 to SSI Output 1.
Typically, channel 1 will act as an SSI device, in which case SSI Output Mode should be set to Slave.
Set the remaining parameters as required.

Bidirectional Communication Between Two RMCs
See below.

Configure Bidirectional Communication Between Two RMCs

The UI/O module can be used to communicate between RMCs.

Configure the UI/O module on the first RMC as follows:
1. In Channel 0:
  - Choose SSI Output mode.
  - Set the SSI Output Mode to Slave.
  - In the Source of Output Data section, choose the register that contains the data to be sent. Typically this is a variable.
  - Set the SSI Data Bits to 32.
2. In Channel 1:
  - Choose SSI Register Input mode
  - Set the SSI Input Mode to Standard
  - Set the SSI Termination to ±Data.
  - In the Location to store SSI Data section, choose the register where the received data will be stored. This must be a variable.
  - Set the SSI Data Bits to 32.
Configure the UI/O on the second RMC as follows:
1. In Channel 0:
  - Choose SSI Register Input mode
  - Set the SSI Input Mode to Standard
  - Set the SSI Termination to ±Data.
  - In the Location to store SSI Data section, choose the register where the received data will be stored. This must be a variable.
  - Set the SSI Data Bits to 32.
2. In Channel 1:
  - Choose SSI Output mode
  - Set the SSI Output Mode to Slave.
  - In the Source of Output Data section, choose the register that contains the data to be sent. Typically this is a variable.
  - Set the SSI Data Bits to 32.
Wire Channel 0 on the first RMC to Channel 0 on the second RMC as shown in RMC150 UI/O Wiring. Wire Channel 1 on the first RMC to Channel 1 on the second RMC.
Click OK.
The RMCs will automatically send data back and forth to each other.