Appendix E-2 Processing Time - Mitsubishi Electric FX3U-ENET-ADP User Manual

FX -ENET-ADP User's Manual
3U

Appendix E-2 Processing Time

Calculate the minimum processing time for MC protocol using the expressions below.
Note that the processing time may become longer depending on the load factor on the network (how
congested the line is), the window size of each connected device, the number of connections used
concurrently, and how the system is configured. Use the values obtained from the expressions below as a
guideline for the processing time when communication is performed using only one connection.
• Minimum processing time of communication using MC protocol (batch read and batch write)
Tfs = Ke + (Kdt
external device
Tfs : Time from when Ethernet adapter receives request data from personal computer until it
completes processing (unit: ms)
Ke, Kdt : Constant (refer to the table below)
Df : Number of request data words + number of response data words (Application data part)
Scr : Scan time
*1. The timing sequence from when the Ethernet adapter receives the request data from the personal
computer until it completes processing is shown below.
External device
(personal computer)
Ethernet adapter
PLC scan time
Batch read
Batch write
[Calculation example 1]
Calculate the required time (unit: ms) to complete the processing of a data request from a PC after receiving
it, when the Ethernet adapter and the PC perform TCP/IP communication and read 32 points of ASCII code
data from the data register (D) in the PLC using MC protocol communication.
• Assume that the scan time of the Ethernet adapter installed station is 40 ms:
52.37 + ACK processing time of the external device (ms)
8 + (0.056
[Calculation example 2]
Calculate the required time (unit: ms) the Ethernet adapter takes to complete the processing of a data request
from a PC after receiving it, when the Ethernet adapter and the PC performs TCP/IP communication and
writes 32 points of ASCII code data to the data register (D) in the PLC using MC protocol communication.
• Assume that the scan time of the Ethernet adapter installed station is 40 ms:
52.37 (ms)
Df) + Scr number of scans required for processing + ACK processing time of
Command
ACK
(TCP only)
message
Step 0
Communication content
Data communication using binary code
Data communication using ASCII code
Data communication using binary code
Data communication using ASCII code
(12 + 66)) + 40 1 + ACK processing time of the external device
Command data length = 12 words
Response data length = 66 words
8 + (0.056 (76 + 2)) + 40
Command data length = 76 words
Response data length = 2 words
*1
Response ACK
message (TCP only)
Step 0
END
Tfs
Communication using TCP/IP
Ke
8 0.054
8 0.056
9 0.049
8 0.056
1
Appendix E: Document, others
Appendix E-2 Processing Time
END
Communication using UDP/IP
Kdt Ke
8 0.059
7 0.067
7 0.051
8 0.051
B
C
D
E
Kdt
149