7 Start-Up
System Manual Modular Systems
Page 64 of 114
HI 800 191 E Rev. 2.02
3. In the Detail View, open the tab with the required channels.
The system variables for the channels appear.
Use of Digital Input
To use the value of a digital input in the user program
1. Define a global variable of type BOOL.
2. Enter an appropriate initial value, when defining the global variable.
3. Assign the global variable to the channel value of the input.
4. In the user program, program a safety-related fault reaction using the error code
-> Error
Code [Byte].
The global variable provides values to the user program.
For digital input channels for proximity switch internally operating in analog mode, the raw value
can also be used and the safe value can be calculated in the user program. For more
information, see below.
To get additional options for programming fault reactions in the user program, assign global
variable to
DI.Error Code
and
Module Error Code
. For more information on the error codes,
refer to the manual of the corresponding compact system or module.
Use of Analog Inputs
Analog input channels convert the measured input currents into a value of type INT (double
integer). This value is then provided to the user program. If analog inputs of type FS1000 are
used, the range of values is 0...1000, with analog inputs of type FS2000, the range of values is
0...2000.
To use the value of an analog input in the user program
1. Define a global variable of type INT.
2. Enter an appropriate initial value, when defining the global variable.
3. Assign the global variable to the channel value
-> Value [INT]
of the input.
4. In the user program, define a global variable of the type needed.
5. In the user program, program a suitable conversion function to convert the raw value into a
used type and consider the measurement range.
6. In the user program, program a safety-related fault reaction using the error code
-> Error
Code [Byte].
The user program can process the measuring in a safety-related manner.
If the value 0 for a channel is
within the valid measuring range
, the user program must, at a
minimum, evaluate the parameter
Error Code [Byte]
in addition to the process value.
To get additional options for programming fault reactions in the user program, assign global
variable to
AI.Error Code
and
Module Error Code
. For more information on the error codes, refer
to the manual of the corresponding compact system or module.
Use of Safety-Related Counter Inputs
The counter reading or the rotation speed/frequency can be used as an integer value or as a
scaled floating-point value.
In the following sections,
xx
refers to the corresponding channel number.
To use the integer value:
1. Define a global variable of type UDINT.
2. Enter an appropriate initial value, when defining the global variable.
3. Assign the global variable to the integer value
Counter[xx].Value
of the input.
4. In the user program, program a safety-related fault reaction using the error code
Counter[xx].Error Code
.
