Block sequential startup of equipment «CASCAD»
The software part
To reduce the start-up loads when the large amount of equipment at the facility is used block sequential startup of equipment – a function block CASCAD.
Processes input values state controlled equipment and generates a consistent issue pulses to discrete unit outputs, which are transmitted to the machine control algorithms for generating automatic A_START teams. If the control algorithm (eg, a fan) comes from the momentum of the cascade unit run equipment, the algorithm starts running (fan start). Location of inputs and outputs of the block are divided into ten groups, such as IN1 corresponds to OUT1, etc. If all ten binary inputs are activated (TRUE), the pulses at the output of the function block channels do not pass.
The unit supports the ability to supply additional pulses on those pieces of equipment which, for one reason or another have not been able to join immediately. Moreover, if the algorithm, which is served A_START impulse is able to run the equipment belonging to the (automatic mode and there is no lock), the equipment is activated.
The logic function block allows you to change the time span between the start attempts of equipment that is set on the block input (WAIT). This delay time is only valid in the absence of state inputs (IN1 … 10 – FALSE), if any digital input is active, then it has no effect on the delay. Function block skip this step, without giving impetus to the corresponding output, and proceeds to the next step. Thus, the delay (WAIT) operates solely on the equipment, which has not yet been included. The pulse length is set statically and is 2 seconds. Selection Output for monitoring the transition states of the bloc. If the output is set to “2”, then the step IN1 – OUT1, if the “7”, then IN6 – OUT6, etc. It provides for protection of the functional unit of the possibility of submitting simultaneously two or more teams, making the launch of safety equipment. If START input channel is disabled (FALSE), the function block is no longer handle their digital outputs.
Assignment of inputs and outputs of the function block
|START||BOOL||Permission to start the block||Selection||INT||Block step position|
|IN1||BOOL||Status of the first fan||OUT1||BOOL||The command to start the first fan|
|IN2||BOOL||Status of the second fan||OUT2||BOOL||The command to start the second fan|
|IN3||BOOL||Status of the third fan||OUT3||BOOL||The command to start the third fan|
|IN4||BOOL||Status of the work of the fourth fan||OUT4||BOOL||The command to start the fourth fan|
|IN5||BOOL||Status of the fifth fan||OUT5||BOOL||The command to start the fifth fan|
|IN6||BOOL||Status of the sixth fan||OUT6||BOOL||The command to start the sixth fan|
|IN7||BOOL||Status of the seventh fan||OUT7||BOOL||The command to start the seventh fan|
|IN8||BOOL||Condition of the eighth fan||OUT8||BOOL||The command to start the eighth fan|
|IN9||BOOL||The state of the ninth fan||OUT9||BOOL||The command to start the ninth fan|
|IN10||BOOL||Condition of the tenth fan||OUT10||BOOL||The command to start the tenth fan|
|WAIT||TIME||Time range between pulses|
The functional block of the cascade start can be used in a fairly wide range of automation industries. Its main distinguishing feature is the delivery of impulse commands to start devices in algorithms that are equipped with self-picking circuits.
Recommendations for useRussian version