ada 3 buah System Compressor kami yang menggunakan PLC Controllogix (atau istilah barunya, PAC=Programmable Automation Controller) dengan program yang typical (alias hampir sama) kecuali setting MODBUS Address (untuk HMI Monitoring di Control Room) dan setting alarm & shutdown (tergantung kondisi engine dan compressornya).
Nah Controllogixnya dipasang CF Card (Non Volatile Memory).
Ada kasus dimana apabila power loss (misal Power Black Out atau Fuse Power Putus) maka setting Modbus dan Seting Alarm&Shutdown di salah satu system compressor jadi berbeda dengan setting terakhir.
Akhirnya setelah ada kesempatan cek di controller properties dengan membandingkan masing2 program Compressor secara online di dapatkan di tab “non volatile memory” ternyata perlakuan load memorynya berbeda.
Ketika Power Up maka Controller di compressor yang bermasalah tsb akan mengambil program yang tersimpan di CF Card tsb. Jadi ini bisa menjelaskan kenapa saat power up, program jadi berubah setting-settingnya.
Untuk itu nanti akan direncanakan perbaikan apabila unit compressor di shutdown.
Berikut info dari HELP nya program RSLogix5000
Perform Nonvolatile Memory Operations
The Nonvolatile Memory tab of the Controller Properties dialog serves as the starting point from which you can perform nonvolatile memory operations. Click the Load/Store button to access the Nonvolatile Memory Load/Store dialog, from which you can perform the actual operations.
The Nonvolatile Memory tab also provides you with status information that indicates any conditions that might prevent you from loading or storing. Possible status messages include:
§ Nonvolatile memory not present
§ Nonvolatile memory not available in the current module redundancy state
§ Controller being edited by another user
§ No controller image or stored controller image
§ Controller not in Program mode
§ Stored image revision in nonvolatile memory does not match controller revision
Controller Properties Dialog Box – Nonvolatile Memory Tab Overview
The Controller Properties dialog displays controller configuration information for the open project and, when online, for the attached controller.
The Nonvolatile Memory tab provides you with access to nonvolatile memory operations.
Note: This tab is available only when the selected controller supports nonvolatile memory.
The name of the stored controller image that resides in nonvolatile memory.
The controller type for the image stored in nonvolatile memory. This controller type can be any type that supports nonvolatile memory.
The firmware revision of the controller when the image in nonvolatile memory was stored. In order for the image in nonvolatile memory to be loaded back into controller memory, the firmware revision of that image must match the revision of the controller.
– Load Image
The condition under which the image stored in nonvolatile memory is loaded back to controller memory. Available conditions include:
§ On Corrupt Memory – this will cause a load whenever there is no project in the controller and you turn on or cycle power on the chassis. If you are using a battery the controller, selecting this option performs a load only if the battery has failed to maintain the project during a loss of power.
§ On Power Up – this will cause a load whenever you turn on or cycle power on the chassis. If you are using a battery on the controller, selecting this option performs a load even if the battery has maintained the project during loss of power.
§ User Initiated – choose this option if you want to load only through RSLogix 5000 software.
Regardless of the currently-selected load option, you can always manually initiate a load as well.
The mode the controller enters upon loading from nonvolatile memory. Choose from:
§ Program (Remote Only)
§ Run (Remote Only)
The Load Mode only applies if the controller keyswitch is in the remote position when loading. If the controller keyswitch is in Run or Program the controller will be returned to that mode once the load is complete. The controller keyswitch always has priority over the Load Mode.
The Load Mode only applies if the Load Image selection is On Corrupt Memory or On Power Up. If the Load Image is User Initiated, the Load Mode is disabled.
Descriptive information that you entered at the time the image was stored in nonvolatile memory. You may enter up to 128 text characters.
The workstation date and time when the image was stored in nonvolatile memory.
Click this button to access the Load/Store dialog.
This button is disabled when:
§ nonvolatile memory is not present in the controller
§ the controller is in Run mode
§ another user has locked the controller
§ the current module redundancy state prevents nonvolatile memory operations
§ the controller is offline
If the Load/Store button is disabled, the status bar indicates the reason. Note that the status bar will display only one status at a time, and you must work through each of them to enable the Load/Store button.
Click this button to accept your changes and close the Controller Properties dialog.
Click this button to cancel your edits.
Click this button to apply your edits and continue editing in the Controller Properties dialog.
Click this button for help on the Controller Properties – Nonvolatile Memory tab.
Berikut tambahan info petikan dari web AB.
Memory cards offer nonvolatile memory to permanently store a user program and tag data on a controller. The 1756-L7 ControlLogix controllers come with a 1784-SD1 Secure Digital card already installed. The 1756-L6 controllers support optional CompactFlash cards that you purchase separately. Through RSLogix 5000 software, you can manually trigger the controller to save to or load from nonvolatile memory or configure the controller to load from nonvolatile memory on powerup.
The GuardLogix controller does not support user program storage or retrieval by using a CompactFlash card.
|Memory||64 MB||128 MB||1 GB||2 GB|
|Supported controllers||ControlLogix L6 controllers||ControlLogix L7 controllers|
|Weight, approx.||14.2 g (0.5 oz)||1.76 g (0.062 oz)|