User Manual

Siemens Building Technologies PROFIBUS DP/P-bus link
Building Automation User's guide 4-3
4.2 Analog modules
The DESIGO I/O range incorporates various analog modules for the connection of sensors
and/or loads/actuators. The following describes the principles of the SIMATIC S7 analog value
display and the display of DESIGO analog values in the format required by SIMATIC S7.
4.2.1 Analog value display
The digitized analog value is the same for input and output values in the same nominal range.
The analog values are displayed in two’s complement format. The analog value sign (+/–) is
always located at bit number 15.
• A value of 0 represents the plus sign (+)
• A value of 1 represents the minus sign (–)
If the resolution of an analog value is less than 15 bits, the analog value is displayed left-
justified. The bits marked “x” are set to “0”.
Note
This resolution does not apply to temperature values. The converted
temperature values are the result of conversion in the analog module
or the DP/P-bus link. (See Tab. 4-3 to Tab. 4-5)