Back to Items IndexItem - Step Master
Please refer to Adding a New Item for specific information on how to add an ITEM and how to change its properties.
Description
The Step Master ITEM is the main ITEM when setting up a Step Control.
The Step Control is to be contained within one TASK, each TASK having only one Step Control.
Each Step Control is to have only one Step Master ITEM.
The Step Master ITEM will search the TASK it is in and find all of the other Step ITEMS. It will search each ITEM in its own TASK in order from first to last. The first Step ITEM found will become the first step, the second Step ITEM found will become the second Step and so on.
When the Step Control is run, it will get the relevant information from each respective Step.
Remember to ensure that all of the Step ITEMS are placed before the Step Master ITEM. This will mean that as the TASK is updated the Step Items , and their respective supporting ITEMS, will be updated first so that when it is the Step Master 's turn to be updated it will have access to the very latest information from the Step ITEMS and their supporting ITEMS. For more information on the sequence in which ITEMS are updated refer to Overview Operation.
Properties
| Class Name | A unique name for this item. The class name is display only and cannot be changed. |
| Name | Enter a meaningful name for this Item so that you, and other people, will easily recognize what it is for. |
| Enabled | No - The ITEM is not enabled and will not update
when its TASK updates Yes - The ITEM is enabled and will update when its TASK updates. |
| PV Input | Select the ITEM that is getting the PV. |
| Step 1 PV Start | Select either option: No = When the Step Control starts the starting Set Value will be "Step 1 SV Start" listed below. Yes = When the Step Control starts the starting Set Value will be the set to the value of the current PV. |
| Step 1 SV Start | Set the Set Value that will be used as the
starting Set Value for the Step Control. Note: Only used when "Step 1 PV Start" above is set to "No". |
| Run Input | Select the ITEM that is getting the Run signal
for the Step Control. The Run Input needs to be set (=1) for the Step Control to run. As soon as the Run Input is set to 0 then the Step Control will stop, irrespective of its position, setting the SV to the Set Value of the last Step. For other Run options refer to Run Options. |
| Run Reset | Select the Output Tag that will reset the Run
signal at the end of the Step Control. This option is only used if the "Run signal" is from a "digital input" which can be reset by a "digital output". Otherwise leave this property blank. |
| Hold/Manual Input | Select the ITEM that is getting the Hold signal. If the Hold signal = 1 then the Step Control will go into "Hold Mode". During this time the Step Control will stop writing the SV to the controlling device. This will enable manual control of the SV if required. Also the Time Used by the Step will not be increased. |
| SV Output | Select the MicroScan Output Tag for the Set Value. |
| On PC Restart | Step Control OFF - Stops the Step Control when
the PC Restarts. Step Control Resume - Resume s the operation of the Step Control to what it was the last time the TASK was updated when the PC restarts. |
| Prev Step Signal | Select the ITEM that gets the signal for the
Previous Step. When this signal is high (=1) then the Step Control will go to the beginning of the previous Step. Refer to Note 2. |
| Prev Step Time | Select the ITEM that gets the signal to decrease
the Time Used of the current Step. When this signal is greater than 0 then the value of the signal will be taken off the value of the current Step's Time Used. Note that the value is in the same units as the respective Step's property "Step Time Interval". Refer to Note 2. |
| Adv Time Signal | Select the ITEM that gets the signal to increase
the Time Used of the current Step. When this signal is greater than 0 then the value of the signal will be added to the value of the current Step's Time Used. Note that the value is in the same units as the respective Step's property "Step Time Interval". Refer to Note 2. |
| Adv Step Signal | Select the ITEM that gets the signal for the
Advance Step. When this signal is high (=1) then the Step Control will go to the beginning of the next Step. If the current Step is the last Step then this will end the Step Control. Refer to Note 2. |
| Dev Alarm Output | Select the MicroScan Output Tag for the Deviation
Alarm. The Deviation Alarm will alarm if it is enabled within the current Step and if the PV has been outside the limits for the time specified by the "Dev Alarm Delay". The "(Gua) Dev Hi" and "(Gua Dev Lo" limits and the "Dev Alarm Delay" values are specified in the current Step. |
| Gua Alarm Output | Select the MicroScan Output Tag for the
Guaranteed PV Alarm. The Guaranteed PV Alarm will alarm if it is enabled within the current Step and if the PV has been outside the limits for the time specified by the "Gua Alarm Time". The "(Gua) Dev Hi" and "(Gua Dev Lo" limits and the "Gua Alarm Time" values are specified in the current Step. |
| Reset Run Input | If the "Run Input" tag above has been set to "No Scan" then select the same Input Tag again to have it automatically Reset when the Step Control has finished. |
Notes