Flowserve MX/QX Profibus DP/PA Field Unit - Manual (Page 41)

41
PB DPV1 / PA Field Unit Installation and Maintenance FCD LMENIM2336-03 – 12/12
flowserve.com
Execution of a function block, physical block or transducer block will be controlled by the mode
parameter. Mode sub-index values are defined as follows:
1. Target – This is the mode requested by the operator. Only one mode from those allowed by the
permitted mode parameter may be requested.
2. Actual – This is the current mode of the block, which may differ from the target based on
operating conditions. Its value is calculated as part of block execution.
3. Permitted – Defines the modes which are allowed for an instance of the block. The permitted
mode is configured by the block design group, i.e., is defined for every block in the according
data sheet. Any mode change request will be checked by the device to ensure that the request
target is defined as a permitted mode.
4. Normal – This is the mode to which the clock should be set during normal operating conditions.
This parameter may be configured and read by an interface device but is not used by the block
algorithm.
3.3 Analog Input (AI) Function Block
The Analog Input (AI) Function Block (Figure 3.2) is a function block in the PROFIBUS Profile Version
3.0 standard. The AI block can process one of several possible process parameters and make it
available to the network user. The output value from the AI block is in units of percent and contains a
status indicating the quality of that process data. The actuator has several possible process parameters
available in different channels. Use the channel number parameter in the function block to set which
variable to obtain from the transducer block and present to the network user.
There is one AI block in the MX/QX actuator device and three possible channels of data to choose
from:
Channel Channel Name Description
357 AI_POSITION_CHAN Current valve position (percent)
358 AI_ANALOG_INPUT_1_CHAN Value of 4-20 mA analog input 1 (percent)
359 AI_ANALOG_INPUT_2_CHAN Value of 4-20 mA analog input 2 (percent)
Figure 3.2 – Summary of the Parameters of the Analog Input Function Block
AI
Function
Block To Network
OUT
Standard Configuration Parameters
(Acyclic Data)
Example: CHANNEL
Process Parameter
(Cyclic Data)