Anaheim Stepper AA2876 Users Guide

							AA2876 PULSE GENERATOR 
 
 
 
 
• Linear Ramping 
• Adjustable Base and Max Speeds 
• Remote Max Speed Pot  
• Low and High Speed Ranges 
• Independent Acceleration and 
      Deceleration Adjustments 
• Open Collector Pulse Output 
• VCO Input 
 
AA2876-1       STANDALONE PULSE GENERATOR WITH SPECIAL BRACKET AS SHOWN IN FIGURE 3. DPS32PG1    3.5A OPEN FRAME DRIVER W/ PULSE GENERATOR DPD72PG1     7A DRIVER PACK WITH PULSE GENERATOR 
 
 
 
 
 
GENERAL DESCRIPTION  
The AA2876 is a linear ramping pulse gener ator (PG) designed to be used with Anaheim Automations Step Motor Drivers. 
 It has adjustable BASE and MAX speeds and independent adjustm ents for acceleration (ramping up) and deceleration 
(ramping down). 
 
SPEED RANGES  
The AA2876 has an adjustable BASE speed (starting speed)  and an adjustable MAX speed (running speed).  There are 
two speed ranges that are jumper selectable, on JP1.  For the low speed range, the BASE speed can be adjusted from 50 
pulses/sec to 500 pulses/sec and the MAX speed can be adjusted from 50 p\
ulses/sec to 5,000 pulses/sec.  For the high 
speed range, the BASE speed can be adjusted from 200 pulses/sec to 2,000 pulses/sec a\
nd the MAX speed can be 
adjusted from 200 pulses/sec to 20,000 pulses/sec.  Note: it is possible to have a MAX\
 speed that is lower than the BASE 
speed.  The BASE speed potentiometer is on-board; the MAX speed  potenti\
ometer is external (mounted on bracket). 
 
LIMITING THE MAX SPEED  
In some applications, it may be necessary to limit the MAX speed so that the operator does not run the machine o\
r 
system too fast.  Potentiometer R31 can be adjusted to limit  the top speed.  Please note that this only affects the MAX 
speed; the BASE speed is unaffected.  
 
RAMPING 
There are separate adjustments for acceleration and deceleration  .  The ramp times are adjustable from 50 milliseconds to 
1.0 seconds.  This is the time it takes to ramp from the lowest BASE spe\
ed to the highest MAX speed.  In terms of  
acceleration units, the accel/decel rates  are adjustable from 5,000 to 100,000 steps/s
2  on the low speed range and 20,000 
to 400,000 steps/s2 on the high speed range. 
 
PULSE OUTPUT 
The clock pulse output is an open collector type output t hat can sink up to 100mA.  When the AA2876 is used with 
Anaheim Automation drivers, the drivers must be c onfigured for negative going (pulled up) clock inputs. 
 
POWER REQUIREMENTS  
There are three ways to power the AA2876 pulse generator.  It may be pow\
ered by an AC voltage (9-12VAC), an 
unregulated DC voltage (8-15VDC), or by a regulated +5VDC  (see specifications).  When the AA2876 is used with 
Anaheim Automation Driver Packs or transformers, the easiest  way to supply power to the AA2876 is by connecting the 
orange logic windings of the transformer to the AC inputs of the AA2876.  This voltage is typically around 10 VAC. 
 
 
 
#L010009 
  
						

							+5VDC OUTPUT 
Pin 3 of TB2 can be used as a  power input; but when t he AA2876 is powered by an AC voltage or unregulated DC voltage, 
this terminal can be used as a regulated +5VDC output capable of  supplying other devices or circuits with a maximum of 
1.0 Amps.   The actual amount of current that may be drawn from  this output depends on the magnitude and stiffness of the 
AC voltage or unregulated DC voltage.  When loading this outpu t, the unregulated DC voltage (pin 1, TB2) must NOT drop 
below 8VDC.  Up to 1.0 amps may be drawn from this  output as long as the unregulated DC voltage does not drop below 
8VDC.  
 
INPUTS  
(See operating modes) 
 
STOP/RUN
 - When this input is open or logic 1, the PG is  stopped and will not output any pulses.  When this input is 
pulled low to a logic 0, the PG will output pulses at the BASE speed r\
ate if the BASE/MAX input is left open, or logic 1.  
If both the STOP/RUN and the BASE/MAX inputs are at a logic 0, the PG will ram\
p up and output pulses at the MAX 
speed rate.  This input is only used in the Two-input operation. 
 
BASE/MAX
 - This input has two functions.  In the Two-input operat ion, this input selects either BASE speed (logic 1) or 
MAX speed (logic 0).  When this input changes, the PG will ramp from\
 one speed to the other. 
 
In the Single-input operation, this input is used to start and  stop the PG (logic 1=stop, logic 0=run). Upon starting, the 
PG will start running at BASE speed but immediately ramp up to the MAX speed and keep running at the Max speed while 
this input is logic 0.  When this input goes back to logic 1 , the p.g. will either stop immediately, or it will ramp down a nd 
stop when it reaches BASE  speed (depending on JP2 setting).  With Single-input operation, the PG only uses BASE speed 
as a starting speed;  it cannot run at BASE speed  for a while.  The S\
TOP/RUN input is NOT used with Single-input 
operation. 
 
VCO IN
 - A voltage (0 to 5Vdc) can be fed into this input instead of using t\
he MAX speed remote POT.  The AA2876 will 
produce a frequency that is proportional to the voltage on this i nput.  To use this input, the BASE/MAX input must be pulled 
to a logic 0 and the MAX Speed POT disconnected.  Please note that the\
 PG will start at BASE speed (set by the BASE 
speed POT) and ramp to the frequency determined by the voltage fed into the VCO Input.  In m\
ost cases, it is best to set 
the BASE speed POT to the lowest setting when using the VCO Input. 
 
  
						

							OPERATING MODES 
 
1.   TWO INPUT OPERATION
 - see Ramp Profile 1. 
A.  STOP/RUN is pulled low; Start at BASE speed and run for    
             a while at BASE speed  B.  BASE/MAX is pulled low; Ramp up to MAX speed 
C.  Both inputs are still low; MAX speed is reached (keep  running at MAX speed) 
D.  BASE/MAX input is let go, or pulled high and STOP/RUN is  still low; Ramp down to BASE speed 
E.   STOP/RUN is still low; BASE speed is reached 
F.   STOP/RUN input is let go, or pulled high; STOP 
 
 
 
 
 
2.   SINGLE INPUT OPERATION W/ NO RAMPING DOWN*    
see Ramp Profile 2. 
A.  BASE/MAX input is pulled low; Start at BASE speed and  immediately ramp up to MAX speed 
B.    BASE/MAX input is still low; MAX speed is reached  
C.  BASE/MAX input is let go, or pulled high; STOP  immediately  
Note: In this mode, the PG still ramps down internally even though 
pulses stop; so, before starting again, the operator must allow 
sufficient time for the PG to ramp back down to BASE speed.  
Also, the decel adjustment should be set for the fastest ramp 
down. 
 
 
 
 
3.  SINGLE INPUT OPERATION W/ RAMPING DOWN
*  
 see Ramp Profile 3. 
A.  BASE/MAX input is pulled low; Start at BASE speed and  immediately ramp up to MAX speed  
B.   MAX speed is reached 
C.   BASE/MAX input is let go or pulled high; Ramp down 
D.   Automatically stop when BASE speed is reached. 
 
 
* NOTE:  With single input operation, jumper JP2 is used to select 
RAMPING DOWN, or NO RAMPING DOWN.  
						

							 
FUNCTION  JP1 JP2 Speed and Ramp Options 
Function   JP1 JP2 
Low Speed Range  1-2  ----- 
High Speed Range  2-3  ----- 
Ramp Up Only    -----  2-3 
Ramp Up and Down  -----  1-2 
TERMINAL  FUNCTION TB1 Terminals 
Terminal  Function 
1    9-12 VAC INPUT 
2    9-12 VAC INPUT 
TERMINAL FUNCTION TB2 Terminals 
Terminal  Function 
1    +12V UNREG INPUT 
2   0VDC 
3   +5VDC 
4   CLOCK OUT 
5   VCO IN 
6   STOP/RUN 
7   BASE/MAX 
SPECIFICATIONS 
 
POWER REQUIREMENTS 
The AA2876 has provisions for the following power supply inputs: 
  9-12VAC @ 30mA - pins 1 & 2, TB1 
8-15VDC unregulated@ 30mA - pin 1, TB2 
+5VDC regulated @ 30mA - pin 3, TB2 
0VDC reference - pin 2, TB2 
  BASE/MAX Input: pin 7, TB2 (10k ohm pullup) 
Base speed - Logic 1 or open 
Max speed (single input running) - Logic 0 
  STOP/RUN Input: pin 6, TB2 (10k ohm pullup) 
Stop - Logic 1 or open 
Run - Logic 0 
  VCO Input: pin 5, TB2 0 to 5Vdc 
Input Impedance: 1Meg Ohm 
  PULSE OUTPUT: pin 4, TB2 Open collector, sink 100 mA 
Standoff 50 Vdc 
  SPEED RANGES, approximate: Low:  BASE SPEED 50 - 500 pulses/sec  MAX SPEED  50 - 5,000 pulses/sec 
  High:    BASE SPEED 200 - 2,000 pulses/sec MAX SPEED  200 - 20,000 pulses/sec 
  RAMP TIMES: time to ramp from lowest BASE to highest MAX 50 milliseconds to 1.0 seconds 
  ACCELERATION/DECELERATION RATES: 5,000 - 100,000 pulses/s
2  for the Low speed range 
20,000 - 400,000 pulses/s2  for the High speed range 
 
 
POWER SUPPLY OUTPUTS  +5VDC output:  1.0 Amps absolute maximum * 
(see paragraph on +5VDC OUTPUT) 
  +12VDC unregulated output: 1.5 Amps maximum * 
  * No more than 1.5A total can be drawn from both of these 
outputs simultaneously. 
   
 
 
 
 
April 15, 1997