Figure 9.60 shows the Network Assignment dialog which details the following information:
Interface identifies the device.
Station ID displays the unique network station ID assigned to the device.
Station Type describes whether the device is a Master or Slave.
Ident ID is the Identification Number listed in the device's GSD file and granted by the PROFIBUS User Organization to the manufacturer for that specific device.
Figure 9.60. PROFIBUS Network Assignment
The Bus Parameters dialog shown in Figure 9.61displays low-level timing settings that the network will employ:
Slot Time: Monitoring time of the transmitting station (requestor) for receiving a responder acknowledgement. After expiration a retry is carried out according to the entry in "Max.Retry Limit". Moeller Operating Instructions CFG-DP System configurator for PROFIBUS-DP, edition 08/00
Minimum station Delay of Responders: A remote responder can send an acknowledgement to a request telegram when this period has expired. It is the smallest interval between receiving the last telegram bit until sending the first bit of a subsequent telegram.4
Maximum station Delay of Responders: After sending a telegram the requestor may not send another call telegram until this period has expired. It is the greatest interval between receiving the last telegram bit and the transmission of the subsequent first telegram bit. The transmitting station (requestor, master) must wait, after having sent a telegram which is not acknowledged (e. g. broadcast), for this time to expire before it transmits a new telegram.4
Quiet time: This is the time which expires before modulators (modulator settling time) and repeaters (repeater toggle time) are toggled from transmitting to receiving mode. This time must be shorter than the "Min Station Delay of Responders".4
Setup time: Minimum interval ("Reaction time") between receiving an acknowledgement and the requestor transmitting a new call telegram (reaction).4
Target Rotation: Preset nominal target rotation time in which the transmit enable signal (Token) should pass the logical ring. It depends on the difference to the actual token rotation time how much time the master has left for ending data blocks to the slaves. Moeller Operating Instructions CFG-DP System configurator for PROFIBUS-DP, edition 08/00
GAP Actualization Factor: This factor determines the number of token rotations before a new user is added to the Token ring. After the period G x TTR the station polls the logical ring for another user access request.5
Maximum Retry Limit: Maximum number of retries for reaching a station.5
Highest Station: The "Highest Station address" is the highest bus address up to which the master polls the bus for other masters in order to pass the token. This station address may not be lower than that of the master station address under any circumstances.5
Poll Timeout: This parameter determines the maximum time within which the answer must be retrieved by the requestor in a master-master relationship.5
Data Control time: This parameter determines the time within which the Data_Transfer_List is actualized at least once. When this interval has expired, the master automatically transmits its operate state via "Global_Control" command. This time is also affects the auto clear setting, which is used to preset global error handling. The DP master uses the Data_Control_Timer to monitor user data transmission (Data Exchange) with all DP slaves. The master interrupts the communication in DataExchange and resets the outputs of all assigned slaves to fail-safe state, if:
- there is no data exchange with at least one DP slave,
- an existing data exchange is interrupted after a monitoring cycle,
- the option "Auto clear" is set true with "Auto clear modus ON".5
Minimum Slave Interval: This parameter determines the minimum interval between two slave list cycles which the master must follow. Determined is always the value for the slowest slave.5
[4] Moeller Operating Instructions CFG-DP System configurator for PROFIBUS-DP, edition 08/00
[5] Moeller Operating Instructions CFG-DP System configurator for PROFIBUS-DP, edition 08/00
The optimize button will generate the proper values for the fastest cycle time with the devices on the network. After completing the schema and before sending the program to the hardware it is recommended you click the optimize button. If the parameters sent to the PROFIBUS device are not optimized or configured correctly a faulty PROFIBUS parameter error may occur.
F igure 9.61. PROFIBUS Network Configuration Parameters – Bus Parameters
