Input Data Processing
(Original Document)
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Overview
The input signal can be used as binary inputs, counter values or for event recording depending on the parameters set in the Parameter configuration window.
Normally the input data of the ERT 854 10 module is processed by the corresponding EFBs (see EFBs for the 140 ERT 854 10)
Binary Inputs
All inputs of the function block are transferred to the PLC after the third processing stage (i.e. enabling, inverting and debounce filtering) before the chatter filter and edge recognition are performed. The processed values of all 32 inputs are cyclically transferred (every PLC cycle) to the first and second input register word of the 7 word %IW register block of the ERT. The address sequence of the module inputs corresponds to standard digital input modules, i.e. inputs 1 ... 16 correspond to bits 15...0. User confirmation is not necessary because the EFB ERT_854_10 must exist and be enabled. The processed values are available for all 32 inputs independent of their further processing as counter or event inputs. The input processing is always executed according to the configuration, but the ERT copies the processed values from the input immediately after the third input processing stage !
NOTE: If the BoolArr32 output array "Input" of the "ERT_854_10"-Transfer EFB (see ERT_854_10: Data transfer EFB) is configured, the processed values are directly available as Bool values.
Counter Values
All inputs of the function block go through all five input processing stages (i.e. enabling, inverting, debounce and chatter filtering as well as edge recognition). The count operation executes once edge recognition has been performed successfully. For edge recognition which is not set as "both edges", the configured inverting decides if rising or falling edges are counted.
NOTE: It is probably not worthwhile using inversion for the recognition of "both edges"
Counter values are 32 bit totals. The PLC receives a complete sequence (configured as: 8, 16, 24 of 32) of time consistent counter values in a multiplex procedure from the "ERT_854_10" transfer EFB cyclically (see description of the EFB, section EFBs for the 140 ERT 854 10). The EFB sets the values in the configured UDINTArr32 output array "Cnt_Data", without the confirmation of the user. After the transfer of the new counter values is completed, the EFB sets the signal "New Data", a Boolean variable "ND_Count", for one PLC cycle.
NOTE: The transfer of the counter values starts with function block 1 and ends with the last function block which is configured as counter inputs. If a consecutive sequence of function blocks starting with the first block are configured as counter inputs, transfer resources are saved. Since the transfer of the counter values competes with the transfer of the recorded events, faster reaction times for both types can be achieved if an ERT module is fully configured as either a counter or an event input. Binary and status inputs have no effect on this.
Event Logging
This function allows input state changes to be registered in time order with a high resolution. The input state changes are logged with a time stamp with a high resolution. The events can later be shown in the correct sequence. The time stamping of events can be configured so that a group of 1, 2 or 8 inputs can be processed in parallel. All inputs of the function block go through all five input processing stages (i.e. enabling, inverting, debounce and chatter filtering as well as edge recognition). The logging (including time stamping) is done as soon as the edge reaches the edge recognition. For edge recognition which is not set as "both edges", the configured inverting decides if rising or falling edges are logged.
NOTE: Inversion is probably not sensible to use with the recognition of "both edges".
A group of inputs is logged as an event if at least one of the inputs in this group has an edge which has been recognized, i.e.:
Events contain a lot of information in an 8 byte block, including the processed values of all inputs in the group with the corresponding time stamp:
The actual value of the inputs is stored right justified in an event structure byte. The ERT saves up to 4096 events in its battery backed FIFO buffer. The ERT provides error bits (bit 5/6 - PF/PH) for buffer overflow/buffer half full within the "Status" output word which is returned from the "ERT_854_10" transfer EFB. Individual events are transferred in a "ERT_10_TTag" structure to the PLC by the "ERT_854_10" transfer EFB. After processing the events, the user must actively signal readiness for the receiving of new events. See EFB description ERT_854_10: Data transfer EFB. If desired, the parameter "Complete time report" can be selected to provide the month and year. For this purpose, there is a special pseudo event without values which contains the complete time information with month and year. The event is marked as a "Complete time report" and precedes the "actual", time stamped event. (See additional information about "Complete Time Report" in Parameters and Default Values).