AMS DCB-274 manual Loop on Port, Lower case L Option Flags, Flags and Numbers

ADVANCED MICRO SYSTEMS, INC.				SMC-27X2 SOFTWARE
Command	Function		Type		NV Bytes
L	Loop on Port		Program		3
	Mnemonic	Data 1		Data 2	Result
	(Name) L (a, c)	0-2048		Condition (0-9)	None

L (Loop on Port)

Loop on Port will test the specified input port for the required condition (c). If the port is NOT at the required level then the program will jump to the specified address. If the address is to a previous instruction then the program will loop until it becomes the specified level. The program will then continue to the next step. The PLC mode inverts the input high/low definitions.

Input ports are available as follows:

Port	Low	High
1	0	1
2	2	3
3	4	5
4	6	7
5	8	9

The SMC-27X2 can view all ports as inputs and outputs, restricted by contention with external hardware. Any “output” port can be modified, then subsequently used in conjunction with the L, G 2048, or A129 (read) command. The SMC-27X2 has an additional feature of implementing a “wait till” function. The standard loop tests the condition every 2-3ms. If the unique address is 2048, the controller executes a tight loop at this instruction, monitoring the specified condition. When the condition is met, program execution continues.

This feature is helpful in situations where the condition may be of short duration. This command is usable only in NV memory program execution. Following is an example of this command:

P 0		Enter program mode.
L0 4		Stay at location 0 until port 3 is low then go to next command in program.
+ 1000		Move 1000 steps in the plus direction.
P		Exit program mode.
Command	Function			Type		NV Bytes
l	Hardware Options			Default, Immediate, Program		2
	Mnemonic		Data 1		Data 2	Result
	(Name) l (a, d)		Option Flags			None

l (lower case L; Option Flags)

IMPORTANT – DO NOT CHANGE JUMPERS WITH POWER APPLIED

This command configures several options, primarily relating to input/output operating modes and defining external hardware. Several options invert the sense of input signals. If appropriate jumpers or input signal inversion is not matched to the selected option(s) then the system may lock up or motion can be inhibited.

Flags and Numbers

Several commands use “on-off” flags to enable or disable some feature. The data supplied is in decimal ranging between 0 and 255. The corresponding binary bits are called flags. There are 8 flags, each equaling binary values of 1, 2, 4, 8, 16, 32, 64, 128.

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