Grundfos CIU 501 User Manual

English (GB)
46
12.2.4 Operation
When powering on CIU 260 with the correct APN setting, the
following APN connection sequence will take place:
1. CIU 260 locates the APN service. The connection state
changes from "Detached" to "Attached".
2. CIU 260 attempts to connect to the APN it has been given and
requests an IP address. The base station looks through its
record of legal SIM cards and finds the IP address, the
address associated with this SIM card, to assign to CIU 260.
After CIU 260 has got the IP address, the connection state
changes to "Context active".
3. CIU 260 is now ready for a client, for example SCADA
system, to establish a socket connection and begin TCP/IP
data exchange. When a client connects CIU 260, the
connection state will change to "Connected", and cellular
connection status LED1 will indicate when data transfer takes
place. See section 5.5 Status LEDs.
A client, for example SCADA, establishes connection to CIU 260
by specifying the IP address and the TCP port 502. Data transfer
is always initiated from the client in the form of a Modbus TCP
telegram embedded in a TCP/IP frame and directed to TCP port
502. To the client software, the connection to CIU 260 is
completely transparent.
The protection against unauthorised data access is high. The
access to the APN network from the Internet can only take place
via the VPN tunnel. See fig. 34. Moreover, data transfer requires
a Modbus master client, knowledge of the Modbus functional
profile and the use of a SCADA PIN code, if enabled.
CIU 260 supervises the APN connection system to ensure that it
is still working. An automatic procedure ensures restarting of CIU
260 and repetition of the APN connection sequence in case a
deadlock situation has occurred. It also closes down socket
connections that are left open by the client and unused for more
than 24 hours.
It is possible to use SMS communication while data
communication is active. However in the "Connected" state, the
delay time between reception and reply increases.
If the connection state is different from "Connected", it is possible
to establish a call-up connection. When the call-up connection is
established, APN data exchange will be blocked until the call-up
is terminated by the caller.
A total of three Modbus clients can be connected to the Modbus
TCP port of the CIU 260 and communicate simultaneously. Each
connection, called a socket connection, is handled independently.
If all three sockets are used simultaneously, a "Silence time-out"
of only one minute is used to prevent complete occupation for a
long time.
Fig. 33 Data connection directly from a PC to CIU 260
Fig. 34 Cellular connection via VPN tunnel
When no data is being transferred, the connection
states "Attached", "Context active" and "Connected".
All show the same LED1 status (short pulse).
TM04 7309 4718
PC Tool, etc.
Cellular network
Base station APN
CIU 260
with
CIM260
and SIM
card
Mobile phone
"Static" IP
address
Setup, status
and control
commands via
SMS
Cellular
"Static" IP address
TM04 7129 4718
PC Tool, etc.
SCADA system
Clients
LAN
GRE router
GRE router
VPN tunnel
Internet
Cellular operator
Cellular network
Base station APN
CIU 260 with
CIM 260 and
SIM card
Mobile phone
"Static" IP address
Setup, status
and control
commands via
SMS
Cellular

Grundfos CIU 501 Specifications

General

Brand	Grundfos
Model	CIU 501
Category	Controller
Language	English