Schneider Electric 58 TRX User Manual

09/2003

©

 2000–2003 Schneider Electric All Rights Reserved

The following sections describe the possible assignments of the Logic Inputs 
(LIx) on the drive controller and the optional I/O Extension Cards. Logic Input 
1 (LI1) is configured for Run Forward when the drive controller is set for two 
wire control and configured for STOP when the drive controller is set for three 
wire control. In three wire control, Run Forward requires a logic input. Run 
Reverse, if used, requires another logic input. 

A logic input is assigned to reverse the direction of operation. The factory 
default is for logic input LI2 to be used to reverse operation. To disable this 
function (for example, when using the controller with a single-direction 
motor), configure for no assignment or re-assign LI2 to another function.

Alternate ramp switching allows switching between two sets of acceleration 
and deceleration ramp times, with each set being adjusted separately. A logic 
input can be assigned to switch between the two sets. A frequency threshold 
may also be configured for ramp switching; see page 45.

Ramp switching is particularly suited for the following:

• Material handling applications that require smooth starting and approach.

• Applications involving fast, steady-state speed correction.

• High-speed lathes with limitation of acceleration and deceleration above 

certain speeds.

An example of using a logic input (LI4) to switch between two sets of ramps 
is shown to the left.

This function pulses motor operation using minimum ramp times (0.1 s), 
limited speed, and delay time between two pulses. To use this function, 
assign a logic input to jog. Jog direction is provided by the operating direction 
command. This function is particularly appropriate for the following 
applications:

• Machines requiring some manual operation during the process.

• Gradual advancement of equipment during a maintenance operation.

The graph to the left portrays a typical jogging operation. The speed 
reference adjusts between 0 and 10 Hz (preset at 10 Hz) and the delay (tm) 
between jog pulses adjusts from 0 to 2 s (preset at 0.5 s).

This function is also referred to as the motorized potentiometer function. It 
allows the speed reference to be increased using one logic signal. The speed 
is maintained when the + speed input is opened. The maximum speed is 
given by the reference applied to the analog inputs. For example, connect AI1 
to +10 Vdc. To use this function, one or two logic inputs must be re-assigned. 
This function is appropriate for:

• Applications involving centralized control of a machine composed of 

several sections operating in one direction.

• Controlling a material handling crane operating in two directions with a 

pendant control station.

Examples of this function are shown in the illustration to the left.

Forward

or

Reverse

t

t

f(Hz)

 0

1

LI4

1

t

Acc  2

Dec 2

Acc  1

Dec 1

HSP

T

or

q

Red.e

p

s

 0

Acceleration 1/Deceleration 1: Adjustment 0.05 to 999.9 s, preset at 3 s
Acceleration 2/Deceleration 2: Adjustment 0.05 to 999.9 s, preset at 5 s

tm

f (Hz)

Forward

or

Reverse

Jog

1

0

1

0

JogOp.eps

Forward

LSP

LSP

0

0

0

2nd action

1st action

a

a

a

a

a

a

a

b

b

c

c

d

Reverse

2nd action

1st action

Motor

Frequency

LI1

a

c

max. speed reference

b

d

LIx

LIy

ATV58 terminal strip

+ 24

AIX

LI1: Forward
LIx: Reverse
LIy: +Speed

Activate a or c, then 
activate b or d.

+

S

pe

ed d

o

u

b

le

 act

ion

 (

c

at

al

og

).

ep

s

+_

- S

p

ee

d D

o

u

b

le A

c

ti

o

n

.e

ps