Galil DMC-1800, DMC-1700 user manual Program Flow Commands, Operands, Debugging Example

interrogation command, LS (List). To list the application program labels only, use the interrogation command, LL (List Labels).

Operands

In general, all operands provide information which may be useful in debugging an application program. Below is a list of operands which are particularly valuable for program debugging. To display the value of an operand, the message command may be used. For example, since the operand, _ED contains the last line of program execution, the command MG _ED will display this line number.

_ED contains the last line of program execution. Useful to determine where program stopped. _DL contains the number of available labels.

_UL contains the number of available variables. _DA contains the number of available arrays.

_DM contains the number of available array elements. _AB contains the state of the Abort Input

_LFx contains the state of the forward limit switch for the ‘x’ axis _LRx contains the state of the reverse limit switch for the ‘x’ axis

Debugging Example:

The following program has an error. It attempts to specify a relative movement while the X-axis is already in motion. When the program is executed, the controller stops at line 003. The user can then query the controller using the command, TC1. The controller responds with the corresponding explanation:

:ED	Edit Mode
000 #A	Program Label
001 PR1000	Position Relative 1000
002 BGX	Begin
003 PR5000	Position Relative 5000
004 EN	End
<cntrl> Q	Quit Edit Mode
:XQ #A	Execute #A
?003 PR5000	Error on Line 3
:TC1	Tell Error Code
?7 Command not valid	Command not valid while running
while running.
:ED 3	Edit Line 3
003 AMX;PR5000;BGX	Add After Motion Done
<cntrl> Q	Quit Edit Mode
:XQ #A	Execute #A

Program Flow Commands

The DMC-1700/1800 provides instructions to control program flow. The controller program sequencer normally executes program instructions sequentially. The program flow can be altered with the use of event triggers, trippoints, and conditional jump statements.

140 • Chapter 7 Application Programming DMC-1700/1800