Siemens SIMATIC ET 200S, Руководство пользователя

Страница: 434 / 652

Analog Electronic Modules
12-28
ET 200S Distributed I/O System
EWA-4NEB 780602402-12
Table 12-28 Response of the Analog Modules, Depending on the Location of the Analog Input Value in the
Range of Values
Measured value is in Input value in SIMATIC S7
Format
Input value in SIMATIC S5
Format
Nominal range Measured value Measured value
Overshoot / undershoot range Measured value Measured value
Overflow 7FFF
H
End of the overshoot range +1
plus overflow bit
Underflow 8000
H
End of the undershoot range --1
plus overflow bit
Before configuration or with
incorrect configuration
1)
7FFF
H
7FFF
H
1)
With 2AI U ST, 2AI I 2WIRE ST, 2AI I 4WIRE ST, 2AI RTD ST, 2AI TC ST with product level 1 the following
applies: If you trigger the configuration error diagnostic message as a result of incorrect configuration (e.g.
wire break at measuring range

20 mA), the SF-LED on the module lights and you can evaluate the
diagnosis. Correct input values are sent to the DP master in this status.
Influence of the Value Range on the Analog Output
The response of the electronics modules with analog outputs depends on the part
of the value range in which the output values are located. The following table
illustrates the relationship.
Table 12-29 Response of the Analog Modules, Depending on the Location of the Analog Output Value in
the Range of Values
Output Value is in Output value in SIMATIC S5/S7 format
Nominal range Value from DP master
Overshoot / undershoot range Value from DP master
Overflow 0--signal
Underflow 0--signal
Before configuration or with incorrect configuration
1)
0--signal
1)
With 2AO U ST, 2AO I ST with product level 1 the following applies: If the configured substitute values are
outside the nominal range, a configuration error diagnostic message is registered and the SF-LED lights.
In this status the output values sent from the DP master are output at the analog output modules.
Use of the shield
We recommend the following with the analog modules to prevent interference:
•
Use shielded cables to the sensors and actuators.
•
Connect cable shields to the shield component.
•
Connect the shield to the ground collector cable.