Descriptions of functions
10.8 Communication via Modbus TCP
SINAMICS DCM DC Converter
Operating Instructions, 12/2018, A5E34763375A
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Drive object that can be addressed via Modbus
With Modbus TCP, you always address the first drive object from the list of drive objects
(p0978[0]). A DC_CTRL drive object must be in this parameter.
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However, Modbus TCP is only activated if, under p0978[0], there is a drive object that is
supported by Modbus TCP.
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If p0978[0] does not contain a valid drive object, then establishing communication is
acknowledged with alarm A08555(2).
Diagnostics LEDs in Modbus TCP
For Modbus TCP, diagnostic states are shown using the following LEDs:
X1400 (CBE20): "OPT" LED
The following states can be displayed using these LEDs:
Color
State
Significance
Green
Continuous
light
Connections and setpoints are OK.
Green
Flashing light Connection is OK, but no setpoints (dependent on timeout).
Red
Flashing light
2 Hz
No connection or setpoint timeout.
10.8.2
Configuring Modbus TCP via interface X1400
Activating Modbus TCP via X1400 (CBE20)
1.
For drive object DO1, set p8835 = 5 (Modbus TCP).
2.
Set the IP address for the CBE20 using p8941.
3.
Set the standard gateway for the CBE20 using p8942.
4.
Set the subnet mask for the CBE20 using p8943.
5.
Set the DHCP mode for the CBE20 using p8944.
6.
Select the setting "Activate and save configuration" as interface configuration using
p8945 = 2.
7.
In the STARTER commissioning tool, check the list of drive object p0978.
If required, change the sequence of the drive objects using the telegram configuration
("Drive device" > "Communication" > "Telegram configuration").
8.
Save the settings in the STARTER commissioning tool and carry out a POWER ON.