Profibus slave configuration

The Configuration steps vary depending upon whether the slave is compact or modular. For both compact and modular slave types, you can specify if the device is enabled or disabled, assign an address, and set a Profibus DP slave's Watchdog Timer. The Watchdog Timer specifies the amount of time before the Profibus DP slave goes into its fail safe mode if communication on the network stops. The Watchdog Timer does not function with Profibus PA slaves. The address is automatically assigned for both compact or modular slaves when the slave is created however, you can change the slave address.

Profibus DP slaves must have an address between 2 and 125; Profibus PA slaves must have an address between 3 and 124. It is recommended that address 1 is reserved for a simplex Profibus DP master and addresses 0 and 1 reserved for a redundant Profibus DP master. Addresses are unique; no two devices, slave or master, can have the same address on a port.

Configuring a compact slave consists of adding the slave to the Profibus master port and setting the slave's properties (enable and Watchdog Timer for Profibus DP slaves). When a compact slave is added to the Profibus master port, the slots and parameters defined for that slave are automatically created below the slave in the DeltaV Explorer hierarchy. Remember that configuration for a compact slave is generated based on a fixed number of Profibus modules in a particular order. Be aware that you cannot delete compact slave slots in DeltaV Explorer; you must delete the slave in order to delete the slot.

Configuring a modular slave consists of adding the slave to the Profibus master port and setting the slave's properties (enable and Watchdog Timer). However, because the configuration for a modular slave is generated based on the number and order of its modules, you configure the device by adding modules (called Slots in a DeltaV system) in the correct order. Depending on the type of module, you may have to add signals or adjust parameter values. Unlike compact devices, modular device slots can be deleted.

Parameters values can affect diagnostics, ground fault detection, failure actions and many other device characteristics. For slaves that have configuration parameters at the slave and or the slot level, it is important to provide parameter values for proper operation of the slave.