Modbus Slave With Modbus/Tcp; Http - JUMO mTRON T Manual

5 Ethernet transmission modes
Chronological sequence
The respective interface searches for all frames configured for it (setup program: CPU > S
> M
ONLY
them in sequence to frame 1, frame 2, and frame 3 as displayed in the image below.
Frame 1
request + answer
actual time spent to transfer all frames
configured scanning cycle
NOTE!
The actual time it takes to transmit all frames can be read under the Modbus addresses
0x00EC and 0x010C (serial) and under the Modbus addresses 0x009D, 0x00B0, 0x00C3,
and 0x00D6 (Modbus/TCP).
If the configured scanning cycle is greater than the elapsed actual time required for scanning,
the central processing unit waits to process the next cycle and thus minimizes the bus load. If
the configured scanning cycle is too short, all configured frames are completely processed cy-
clically without a delay.
5.4

Modbus slave with Modbus/TCP

Here, the central processing unit serves as a slave and is available for requests on the bus from
the Modbus master. A master can request all device variables according to the Modbus ad-
dress tables of this slave.
 Chapter 7 "Modbus address tables", page 77
NOTE!
Only two Modbus masters (clients) can access this slave (server) via Modbus/TCP. A con-
nection opened by a master is canceled after 30 seconds of inactivity of the slave. A closed
Modbus TCP port (by the slave or from the other end) can only be reopened after 10 seconds.
The TCP port no. is a presetting configured to the value 502
5.5

HTTP

In this case, the central processing unit is configured as a slave and handles incoming requests
as a server via port 80. These requests, for example, can be carried out by a PC with setup
program, PC evaluation software (PCA), or PCA communication software (PCC).
60
ODBUS FRAMES FOR READING
Frame 2
request + answer
/ > menu item I
WRITING
Frame 3
request + answer
) and cyclically transmits
NTERFACE
Frame 1
request + answer
. This value can be edited.
DEC
ETUP
t