4. FUNCTIONS
MELSEC-A
4-1
4. FUNCTIONS
4.1
Positioning in the PROFIBUS-FMS Network
The AJ71PB96F/A1SJ71PB96F in PROFIBUS-FMS network is positioned to the following.
(1) The AJ71PB96F/A1SJ71PB96F operates as a master station in the PROFIBUS-FMS
network.
(2) The AJ71PB96F/A1SJ71PB96F contains both client and server functions.
4.2
Bus Parameters
The bus parameters are the communication parameters prescribed for the PROFIBUS protocol No. 2
layer operation. Bus parameters are set using the SW0IX-PROFPE.
The bus parameter rangers and default values that can be set in AJ71PB96F/A1SJ71PB96F are
shown below.
Table 4.1 Bus Parameters Setting Items
Item Unit
Setting
range Default
value
Local address
0 to 126
0
Baud rate
9.6, 19.2, 93.75, 187.5, 500, 1500kbps
9.6kbps
Slot time
Bit Time
37 to 16383
100
Min Tsdr
Bit Time
11 to 1023
30
Max Tsdr
Bit Time
37 to 65535
50
Quiet Time
Bit Time
0 to 127
22
Setup Time
Bit Time
1 to 255
5
Target Rotation Time
Bit Time
256 to 16777215
10000
GAP Update Factor
1 to 100
1
Has
1 to 126
126
Max Retry Limit
0 to 7
1
Remark
Following is an explanation of the terminology used for bus parameters.
Tsdr:
Station Delay Time as Responder
Bit Time:
The time required to transmit 1 bit = 1/baud rate
Slot Time:
The maximum time that the requester must wait for a response from the
responder. Max Tsdr < Slot Time
Min Tsdr:
The minimum time required for the responder to respond.
Quiet Time < Min Tsdr, Setup Time < Min Tsdr
Max Tsdr:
The maximum time required for the responder to respond.
Quiet Time:
The time required for the repeater to switch from the transmission mode to the
receive mode.
Setup Time:
The time required for the requester to switch from the transmission mode to
the receive mode.
Target Rotation Time: If the actual token rotation time becomes larger than this time, cyclic
communication will no longer be possible.
GAP Update Factor:
This shows how many times the station information can be updated for 1 token
rotation.
Station information update interval = G x Target Rotation Time
HSA:
Highest Station Address. The highest address of the stations connected to the
network.
Max Retry Limit:
The maximum number of transmission retries when data transmission fails.
