Mitsubishi Electric MELFA BFP-A8787-F Instruction Manual page 127

(1) Variable extension timing
When the controller is started up while the sequencer direct performance function is valid (both bits 0, 1 of
parameter IQMEM for selecting shared memory extended function are set to one), external program vari-
ables and system state variables are extended.
User defined external variable with the same name is used:
When the user defined external variable with the same name is in use, an error "L4811 User defined
external variable redefinition error" occurs, but the variables for sequencer direct performance are
extended. However, because already created user defined external variable still remains, there are two vari-
ables with same name. In this case, because the extended variables for sequencer direct performance is
preferred for variable reference, the values of extended variables for sequencer direct performance are dis-
played in the variable monitor.
When the sequencer direct performance gets invalid, the user defined external variable becomes available
as before.
Out of memory:
In case of out of memory, errors "C7010 Out of memory" , "L4800 System based program unavailable"
occur. Here, because the system based program itself is not created, the variables are not extended.
Change of parameter PRGGBL (external variable extension)
When the system starts up while sequencer direct performance function is valid, this parameter PRGGBL is
changed to one (valid) even if PRGGBL was set to zero (invalid). The factory default of PRGGBL is one, but
when its value was changed by the user, the valid setting of sequencer direct performance changes the
value.
(2) Deletion timing of extended variables
When the controller is started up while the sequencer direct performance function is invalid (either bits 0, 1
of parameter IQMEM for selecting shared memory extended function is set to zero), extended external pro-
gram variables and extended system state variables are deleted. The user available memory space
increases.
(3) Add controller program check
When the definition (Def Pos P_DM, etc.) of extended variable is tried to be entered into the controller while
sequencer direct performance function is valid, an error "4350 Duplicated variable definition tried" occurs.
(4) Program syntax check
The definition (Def Pos P_DM, etc.) error of extended variable is not checked by syntax check in the RT
ToolBox2 (because the syntax check of RT ToolBox2 cannot determine whether the sequencer direct perfor-
mance function is valid or not). Its error is checked by the controller's program check during transferring the
program to the controller.
(5) Treatment when sequencer direct is performed while the variables were not extended
The sequencer direct performance is not received without variable extension.
The completion status is set to the number indicating an impracticable reason (refer to
tion Command Is Impracticable:").
9Shared Memory Extended Function Relevant Parameter
Parameter of Selecting Shared Memory Extended Function 9-116
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