Galil DMC-1800, DMC-1700 user manual Hardware I/O, Digital Outputs

All input parameters must be converted into these units. For example, an operator can be prompted to input a number in revolutions. A program could be used such that the input number is converted into counts by multiplying

it by the number of counts/revolution.

Example:

#RUN	Label
IN “ENTER # OF REVOLUTIONS”,N1	Prompt for revs
PR N1*2000	Convert to counts
IN “ENTER SPEED IN RPM”,S1	Prompt for RPMs
SP S1*2000/60	Convert to counts/sec
IN “ENTER ACCEL IN RAD/SEC2”,A1	Prompt for ACCEL
AC A1*2000/(2*3.14)	Convert to counts/sec2
BG	Begin motion
EN	End program

Hardware I/O

Digital Outputs

The DMC-1700/1800 has an 8-bit uncommitted output port for controlling external events. The DMC-1750 through DMC-1780 or DMC-1850 through DMC-1880 have an additional 8 outputs. [The DMC-17X8 has an additional 64 I/O (configured as inputs or outputs with CO command)]. Each bit on the output port may be set and cleared with the software instructions SB (Set Bit) and CB(Clear Bit), or OB (define output bit).

For example:

INSTRUCTION	FUNCTION
SB6	Sets bit 6 of output port
CB4	Clears bit 4 of output port

The Output Bit (OB) instruction is useful for setting or clearing outputs depending on the value of a variable, array, input or expression. Any non-zero value results in a set bit.

INSTRUCTION	FUNCTION
OB1, POS	Set Output 1 if the variable POS is non-zero. Clear Output 1 if POS equals 0.
OB 2, @IN [1]	Set Output 2 if Input 1 is high. If Input 1 is low, clear Output 2.
OB 3, (@IN [1]&@IN [2]) Set Output 3 only if Input 1 and Input 2 are high.
OB 4, COUNT [1]	Set Output 4 if element 1 in the array COUNT is non-zero.

The output port can be set by specifying an 8-bit word using the instruction OP (Output Port). This instruction

allows a single command to define the state of the entire 8-bit output port, where 20 is output 1, 21 is output 2 and so on. A 1 designates that the output is on.

For example:

INSTRUCTION FUNCTION

OP6

OP0 OP 255

Sets outputs 2 and 3 of output port to high. All other bits are 0. (21 + 22 = 6) Clears all bits of output port to zero

Sets all bits of output port to one.

(22 + 21 + 22 + 23 + 24 + 25 + 26 + 27)

The output port is useful for setting relays or controlling external switches and events during a motion sequence.

166 • Chapter 7 Application Programming DMC-1700/1800