PROFIBUS Manual
Reset: FMA7 can use this service to reset layers 1 and 2. When FMA1/2 has received the reset it will generate the appropriate reset signal for both layers, transmit it across the relevant interface, and wait for a confirmation from the layers addressed.
Set Value: This optional service can be used to assign specific values to variables in both layers. The variable names and required values are transferred in the instruction. FMA1/2 generates accordingly an FDL and/or PHY-SET-VALUE.request and forwards this to the layer(s).
Read Value: With this optional service variables can be read from both layers. The variable names are transferred in the instruction, upon which FMA1/2 will generate an FDL and/or PHY-READ-VALUE.request and forward this to the layers.
Event: With this service the user is informed about events or errors in the layers. If in either of the two layers an error message of the type PHY-EVENT.indication or FDL-FAULT.indication has occurred, an FMA1/2-EVENT.indication will be generated with FMA1/2 on receipt of the signal and forwarded to FMA7.
Station |
Name of error |
Description |
Master |
Duplicate address |
The station address set is already responding on the bus. |
Master |
Faulty transceiver |
The signal sent cannot be received at the same time. |
Master / Slave |
Time_out |
No bus activity detected. |
Master / Slave |
Not_syn |
No SYN pause found in the specified period. |
Master |
Out_of_ring |
This master will no longer receive the token unless it requests it. |
Master |
GAP_event |
Active station has been re-detected or was lost. |
(R)SAP Activate: With the help of the optional service "SAP Activate" a user can configure and activate an SAP. Overall communication takes place via SAPs (SAP: service access point). They contain the framework of allowed messages and message information (allowed target addresses, allowed data lengths, ...). If a message arrives at an SAP, it will be checked to see if it matches the conditions defined for the SAP. If it does, the message will be forwarded, otherwise an error message will be generated. At first sight, communication via SAPs seems rather cumbersome, but it allows messages and message lines to be checked and potential connection errors prevented. In order to have responder functions with the reply services SRD and CSRD, an RSAP must be set up through the "RSAP Activate" service.
(R)SAP Deactivate: This is the complementary service to "(R)SAP Activate". It lets FMA 1/2 users deactivate an (R)SAP and with it all the connections belonging to that (R)SAP .
