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Functions
(
continued)
NTP time synchronization service
Presentation
The time synchronization service is based on NTP
(
Network Time Protocol)
which is
used to synchronize the time of a client or a server on Ethernet TCP/IP from a server
or another reference time source (radio, satellite, etc.).
Operation
b
Modbus TCP communication modules:
b
BMX NOE 0100/0110 (with version
u
2.0
module) and BMX NOR 0200H for
Modicon M340 Unity version
u
2.0
automation platform
b
TSX ETY 5103 for Modicon Premium Unity
u
V2.0 automation platform
b
140
NOE 771 11 for Modicon Quantum Unity
u
V2.0 automation platform
b
have an NTP client component
These modules can connect to an NTP server using a client request (unicast), in
order to update their local time. The module clock is updated periodically (1 to 120 s)
with an error
y
10
ms for standard processors and
y
5
ms for high-performance
processors.
If the NTP server cannot be reached, the Ethernet Modbus/TCP module switches to
a standby NTP server.
Ethernet module associated with its Unity processor
Precision with respect to the reference clock
Ethernet modules
Unity processors
Clock synchronization
(1)
Event synchronization
Time stamping
(2)
BMX NOE 0100/0110
BMX NOR 0200H
(
Modicon M340 platform)
BMX P34 1
p
+/- 1 ms typical
+/- 10 ms max.
=
Clock
synchronization
precision
+
Cycle time
for fast task
+
Scan time
for I/O
=
Clock
synchronization
precision
+
Scan time
for I/O
BMX P34 2
p
+/- 1 ms typical
+/- 5 ms max.
TSX ETY 5103
(
Modicon Premium platform)
TSX P57 1
p
TSX P57 2
p
TSX P57 3
p
± 1 ms typical
± 10 ms max.
TSX P57 4
p
TSX P57 5
p
TSX P57 6
p
± 1 ms typical
± 5 ms max.
140
NOE 771 11
(
Modicon Quantum platform)
140
CPU 311 10
140
CPU 434 12U
± 1 ms typical
± 10 ms max.
140
CPU 651 50/60
140
CPU 652 60
140
CPU 671 60
140
CPU 672 61
± 1 ms typical
± 5 ms max.
The PLC processor clock is therefore itself updated with a precision of 5 ms for
standard processors and 1 ms for high-performance processors. A function block is
available for reading this clock. In each PLC application, events or variables can be
time-stamped.
The Ethernet module is configured via a Web page. The time zone can be
configured. A time synchronization service (NTP) diagnostic Web page is also
available.
Information on the time synchronization service (NTP) is also available in the
Transparent Ready private MIB, which can be accessed via the SNMP network
management service (see above).
(1)
Time difference between the physical input and the central NTP server.
(2)
With use of an interrupt input module.
Power
supply
Processor
Ethernet
module
Internal
clock
Ethernet network
NTP
server
Premium/Quantum
NTP response
NTP request
(
S)NTP
client
Functions
(
continued)
NTP service configuration
Modicon Premium automation
platform
0
Ethernet Modbus/TCP network
Ethernet Modbus/TCP communication services
NTP service diagnostics
2
1
3
4
5
6
7
8
9
10