In order to communicate with a function block that runs in a fieldbus device, you must use an extended function block in the control strategy diagram. The extended function block resides in the controller and communicates with the function block running in a fieldbus device. Extended blocks are based on standard DeltaV function blocks but may have a slightly different set of parameters. These parameters may be specific to a device manufacturer (and are sometimes called custom parameters). Extended block names include the prefix, FF to differentiate them from the standard blocks.
There are several ways to create an extended block. Refer to Control Studio help for details on these methods.
Assign a standard block to a compatible block in a fieldbus device. In this case, the conversion from standard to extended is performed automatically. An extended block and an extended block of the same type with the _RMT suffix are not considered compatible. If you assign an extended block to an _RMT block of the same type, the block does not pick up the additional parameters in the _RMT block.
Convert an unassigned standard block using the Convert command in Control Studio.
Convert an already assigned extended block to another compatible one. For example, you can convert an FFAI to an FFAI_RMT. The assignment is retained if the device block supports the additional block parameters. The assignment is deleted if the device block does not support the additional parameters of the extended block.
Build a custom palette that includes the extended blocks you want to use and drag them onto the diagram.
Use the Custom Block Assistant.
Use the Physical Block Assistant.
The following table describes each extended block.
Function Block |
Description |
|---|---|
FFAI |
Extended Analog Input block. |
FFAO |
Extended Analog Output block. |
FFARTHM |
Extended Arithmetic block. |
FFCTLSEL |
Extended Control Selector block. |
FFDI |
Extended Discrete Input block. |
FFDO |
Extended Discrete Output block. |
FFINT |
Extended Integrator block. |
FFISEL |
Extended Input Selector block. |
FFISELX |
Extended Input Selector Extended block. |
FFISEL_BASE |
Extended Input Selector block that is a partial block definition containing the common parameters for FFISEL and FFISEL_STD. This block does not exist in any device. |
FFISEL_STD |
Extended Input Selector block (standard). |
FFMAI |
Extended Fieldbus Multiplexed Analog Input block. |
FFMAO |
Extended Fieldbus Multiplexed Analog Output block. |
FFMDI |
Extended H1 Carrier Multiple Discrete Input block. |
FFMDI_STD |
Extended Multiple Discrete Input block. |
FFMDO |
Extended H1 Carrier Multiple Discrete Output block. |
FFMDO_STD |
Extended Multiple Discrete Output block. |
FFPID |
Extended PID block. |
FFSGCR |
Extended Signal Characterizer block. |
FFSPLTR |
Extended Splitter block. |
FFAI_RMT |
Extended Analog Input block with additional parameters supported by the Analog Input block in Emerson devices.(1) Additional parameters are: ALM_SEL, OUT_D |
FFAO_RMT |
Extended Analog Output block with additional parameters supported by the Analog Output block in Emerson devices.(1) Additional parameters are: STDEV and STDEV_CAP. Although these parameters are also visible in the FFAO block, they only act as placeholders. |
FFMAI_RMT |
Extended Fieldbus Multiplexed Analog Input block with additional parameters supported by the Multiplexed Analog Input block in Emerson devices.(1) |
FFPID_RMT |
Extended PID block with additional parameters supported by the PID block in Emerson devices.(1) Additional parameters are: BETA, BIAS, ERROR, FORM, GAMMA, IDEADBAND, SP_FTIME, SP_WRK, STRUCTURE |