Rockwell Automation 1756-L55M12, Selection Manual, Page: 51 / 88

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1756-SG001G-EN-P — March 2004
Determining
Memory
Requirements
The following equations provide an estimate of the memory needed for a controller.
These numbers are rough estimates.
Controller memory boards
The 1756-L55 controllers do not operate stand-alone. Choose one of these memory
boards to come already assembled with the controller. You can also order additional
memory boards either for spare parts or to upgrade existing 1756-L55 controllers.
The 1756-L6x controllers have a fixed RAM size and do not use a memory board. Use
a CompactFlash card for nonvolatile storage. You must remove the controller from the
chassis to access the CompactFlash card.
Non-volatile memory
The nonvolatile memory (flash) lets you permanently store a user program and tag
data on a controller. You can:
y
manually trigger the controller to save to or load from nonvolatile memory
y
configure the controller to load from nonvolatile memory on power up
The 1756-L55M2x controllers have fixed internal nonvolatile memory.
The 1756-L6x controllers support a removable CompactFlash card for nonvolatile
memory. You install the 1784-CF64 card in a socket in the controller. You must
remove the controller from the chassis to install CompactFlash. The CompactFlash
card stores the user program, tag data, and controller firmware. This lets you
upgrade firmware on a 1756-L6x controller without using RSLogix 5000 or
ControlFlash software.
Controller tasks _____ * 4000 =
_____ bytes
(minimum 1 task)
Digital I/O points
_____ * 400 = _____ bytes
Analog I/O points _____ * 2600 = _____ bytes
Communication modules
✶
_____ * 2000 = _____ bytes
Motion axes _____ * 8000 = _____ bytes
✶
When estimating memory use by communication modules, count all the communication modules in the system, not just those in the local chassis.
This includes device connection modules, adapter modules, and ports on PanelView terminals.
Catalog Number:
1756-M12
✶
1756-M13
1756-M14
1756-M16
1756-M22
✶
1756-M23†
1756-M24†
1784-CF64
✶
The 1756-L55 controller must have firmware revision 10 or higher.
†The 1756-L55 controller must have firmware revision 8 or higher.
‡You can use CompactFlash with the 1756-L61, -L62, -L63, and -L60M03SE controllers. The 1756-L61, -L62 controllers require firmware revision 12 or greater. The 1756-L63 controller requires firmware revision 11 or higher. The
1756-L60M03SE controller requires firmware revision 13 or higher.
Supported Controller:
1756-L55
1756-L55
1756-L55
1756-L55
1756-L55
1756-L55
1756-L55
1756-L6x‡
Battery-Backed Static RAM:
750 Kbytes
1.5 Mbytes
3.5 Mbytes
7.5 Mbytes
3.5 Mbytes for tag data
750 Kbytes
1.5 Mbytes
3.5 Mbytes
none
Nonvolatile RAM:
none
none
none
none
750 Kbytes
1.5 Mbytes
3.5 Mbytes
same as the battery-backed static
RAM limit for the controller