Sylk Advanced Properties

Sylk advanced properties

Each piece of information on the Sylk bus has a few advanced properties associated. These are change of value (COV), update rate and fail detect (FD). COV properties are only supported on Sylk I/O outputs and are not available on any other Sylk devices.

COV: Only sends data to the Spyder when there is a change of value equal in magnitude to this value. COV is a property of the Sylk master device (e.g. Spyder) and is currently only supported on the outputs of a PU*6438SR.

For Modulating Inputs/Outputs - When this option is checked, the Sen Delta field gets enabled allowing to enter the required change of value. When Sen Delta field is set to other than zero, value is transmitted to Spyder controller when the change of the value equals in magnitude of this value. If 0 (zero) is entered in the Sen Delta field, any change in the value will be transmitted to the Spyder controller.

For Binary Inputs/Outputs - When this option is checked, Sen Delta shows a value as Zero and sends the data whenever state of the binary input/output changes.

Note:Whenever the COV is enabled, a warning appears as, "COV uses Sylk bandwidth. Excessive use of bandwidth can cause loss of data between Sylk devices. Use COV only for critical points", with the notes:

1. The "Sylk Bandwidth" calculation in the "Resource Usage" view of the control program does not account for COV usage.
2. COV for universal Inputs works only with Sylk IO series 2 or higher. The information regarding Series 1 and Series 2 is available on the label pasted on the device cover.
3. For PUB6438SR, firmware version should be 27.16 or greater. For version lower than 27.16, if user tries to download the program with COV enabled for the Sylk IO devices' Universal Inputs in the Spyder controller, an error message pops up to prompt the user to update the firmware to the right version.

It is recommended to use COV feature on Sylk Bus for critical points. Excessive use of COV feature could overload the messaging on the Sylk bus and cause higher addressed devices not to communicate properly.

Note: Following Sylk Device Model don’t support COV:
1. Sylk Actuator outputs
2. C7400S
Since they don't support COV, the Sen Delta field cannot be edited and the data is transmitted as per Update Rate.

Update Rate: This is the rate at which data is sent from the Sylk device to Spyder and must be entered in increments of 5 seconds. This can be used simultaneously with COV and the user would get the data at both the update rate and whenever the change of value condition is met. The update rate does have a small impact on the bandwidth of the Sylk bus and can be adjusted accordingly if Sylk bandwidth becomes an issue.

FD: Time until the Spyder is notified of a failure on this point. Fail detect is a property of the Sylk slave device (e.g. Sylk actuator or Sylk I/O). On an output, FD can either be unconfigured or 20 for Sylk I/O or unconfigured or 180 for other Sylk devices. On an input, FD can either be unconfigured or 180 for all Sylk devices.