The system requires only one I/O license for references to as many as 16 I/O signal-bearing parameters per device. The system consumes a single license of the most expensive type used. The license costs are (from highest to lowest): AO, AI, DO and DI. For Profibus devices with more than 16 signal parameters referenced by modules, the 15 least expensive I/O parameters do not require a license. The remaining parameters each cause an I/O license demand.
The table shows the signal-bearing parameters that can trigger license demand for a Profibus device.
| Parameter name | I/O license type used |
|---|---|
| FIELD_VAL | AI |
| FIELD_VAL_D | DI |
| OUT | AO |
| OUT_D | DO |
The following table provides an example of 18 DSTs in a Profibus device that consume 3 DST licenses. Note that an AI DST is the most expensive of the least expensive 16 and therefore consumes a license. Additional DSTs (in this case AOs) each consume a license.
| DST type | Uses DST license |
|---|---|
| Discrete Input | No |
| Discrete Input | No |
| Discrete Input | No |
| Discrete Output | No |
| Discrete Output | No |
| Discrete Output | No |
| Discrete Output | No |
| Discrete Output | No |
| Discrete Output | No |
| Discrete Output | No |
| Discrete Output | No |
| Discrete Output | No |
| Analog Input | No |
| Analog Input | No |
| Analog Input | No |
| Analog Input | Yes |
| Analog Output | Yes |
| Analog Output | Yes |