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Outputs of the Jogging Function Block

Enable
output

Power flow output passes power flow when it receives power flow from
the Enable input.

Axis Direction
Output

Boolean  Variable  (Q0005  to  Q0024).  The  Micro  PLC  output  point  for
which  direction  is  to  be  set.  0  =  clockwise,  1  =  counterclockwise.  The
actual  direction  depends  on  the  field  connections  and  drive  settings.
The application program should not override the direction output during
the motion operation.

Active

Boolean variable (%I, Q, M, G, T) for the Jogging Active status. 1 = Jogging
in progress. 0 = Jogging complete or stopped,

Error

Boolean variable (%I, Q, M, G, T) for the error status. Set to 1 if an error
has occurred within function block. See Error ID below.

Error ID

Word variable (%AI, AQ, R). If Error (ER) =1, this is an Error ID. If Warning
(WR) =1, this is the Warning ID. See the list of error definitions on page
371.

Warning

Optional parameter. Boolean variable (%I, Q, M, G, T). Set to 1 when a
warning has occurred. See Error ID above. Warning is generated when
the same motion is triggered again while it is already in progress.

19.4.2

Example Program Logic for Jogging

Figure 217

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19.5

Blending

A  Blended  Move  consists  of  up  to  four  successive  moves  that  are  executed  without  the
output  value  returning  to  zero  between  moves.  The  speed  (pulse  rate)  and  distance
(number of pulses) for each of the blended moves can be defined. Transition to the speed
of the next move uses ramping.  At the end of each blended move, when the motor has
moved the defined number of pulses, the motor must be at the speed set for the next move
in the sequence.

The simplest form of blended move is shown below.

Figure 218

Because each Blend profile is equal to a normal ramping profile, a Pulse train with Ramp can
be done using a Blended move with just one blending profile. Use this method if the
hardware configuration selected is 4 Type A_32 or 1 Type A/1 Type B_32.

Each move can use any of the combinations of Ramp up (acceleration), At Velocity and
Ramp Down (deceleration) states. These combinations depend on velocity of the next
move in the sequence.

The parameters of each profile are used until the velocity of the next move is reached.

Based upon the Number of Pulses and the input parameters, the acceleration, deceleration
and the flat regions of the profile are calculated in order to reach the target frequency of
next profile. The motion is then performed with the calculated parameters.

19.5.1

Examples of Blended Moves

This section describes some different Blended Move operations.

Example 1

In this example, all of the moves have sufficient number of pulses and acceleration to
reach the desired velocity.

Figure 219

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In this example, segments 1, 2, and 3 use the profile 1 parameters:

•

The number of pulses for segments 1, 2, and 3 are from distance 1.

•

Segment 1 accelerates at acceleration 1.

•

Segment 2 moves at velocity 1.

•

Segment 3 decelerates at deceleration 1. For segment 3, while calculating the
number of pulses, the velocity of profile 2 (segment 4) is taken as the final velocity.

Segments 4 and 5 use the profile 2 parameters:

•

Segment 4 moves at velocity 2.

•

Segment 5 accelerates at acceleration 2.

The final aim of each move is to reach the next move desired velocity. So in Profile 1, first
the acceleration pulses are calculated for segment 1, then the deceleration pulses are
calculated for segment 3. The remaining pulses are generated at the profile 1 desired
velocity.

Example 2

In this example, the distance 1 value in profile 1 is not enough to reach velocity 1. So in
profile 2 (segment 2), accel2 and pulses2 are used to reach velocity 2. Velocity 2 and velocity
3 are configured as equal.

Figure 220

Example 3

Figure 221

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In this example, for profile 1:

The acceleration to reach velocity 1 is calculated,

Then the acceleration needed to reach velocity 2 from velocity 1 is calculated.

The remainder of profile 1 is run at velocity 1. In this example, all of profile 1 is
required for acceleration, so there is no constant velocity (dotted line) in profile 1.

Profile 3

–

Like profile 1, distance 3 is just sufficient to accelerate to velocity 4, so profile 3

has no motion at velocity 3.

Profile 4 consists entirely of deceleration.

Example 4

In this example, in Profile 1, the acceleration is just enough to reach velocity 1. In profile 2,
segment 2, deceleration 2 is used to reach velocity 2. Segment 3 of profile 2 is at velocity 2.
Segment 4, ramps up at acceleration 2 to reach velocity 3.

Figure 222

Example 5

In profile 1, segment 1 accelerates from zero to velocity 1 then decelerates down to
velocity 2 from velocity 1 in segment 2. Since the distance is just enough for these
segments, profile 1 has no motion at velocity 1.

Figure 223

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19.5.2

Blending Function Block

The application program uses the following function block to set up and control Blended
Moves operation:

Figure 224

The channel’s Output Enable bit (for example, Q0505 for channel 1) must be set to 1 to use

this or any other motion function block. If the Output Enable bit is not 1, the function will
not execute, and a Channel Enable error will be reported.

When the Enable input receives power flow, if the Execute input is set to 1, the function’s

parameters are loaded. If the parameters are not valid, an error code is generated, and the
Blending function does not start. If the parameters are valid, the function block starts
execution and sets the Active output to 1. The Active output returns to 0 when the function
completes, or is stopped.

If the Enable input continues passing power flow, Blending can be restarted with the same
parameters by generating a low to high transition on Execute input again. To execute the
function block with different parameters, stop the motion. Then, remove power flow from
the Enable input. After changing the parameter values, the function can be executed by
reapplying power flow to the Enable input and generating a low to high transition on the
Execute input.

The function block’s Enable output transitions to 0 automatically when EN input becomes

low.

Transitions of the Execute input are only monitored while the Enable input is receiving
power flow. While the Enable input receives power flow, the Execute input is monitored for
a change in its status from the previous logic scan; if Enable and Execute transition in the
same scan, the transition of Execute is not detected. Therefore, the application logic must
not set both Enable and Execute either low or high in the same scan. If Enable and Execute
were made low in the same scan, the Blending function block would still see the Execute
input as high. If Execute and Enable were made high in the same scan, the Blending function
block would not see the transition in Execute status and motion would not start.

The motion status can be monitored by the Active output of the function block. If the Active
output is 1, motion is in progress. While motion is in progress, the Done, Error, and Warning
outputs should be 0. After the completion of the motion, the Active output is set to 0 and
the Done output is set to 1.

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If the Enable input stops receiving power flow while motion is in progress, the function

block’s Done output will not indicate when motion stops. In this case, the application
program should monitor the Done output bit (bit 2) at address +0 of the function block’s

assigned Instance data to determine when the motion is completed.

When there is any error during the motion or at the start of the motion, the Error indication
and the Error Number are updated to the Error output and the Error ID specified in the
function block.

Stopping Blending

Blending can be stopped by:

•

When the PLC has gone through Run-Stop transition. After coming back to Run
mode, an axis error (0x38) is logged into the %AI002 register and also at the Blending
function block's Error ID output. The error in %AI002 must be cleared using the
predefined reset bits for any other motion to start on that axis.

•

When the PLC is power cycled.

•

Executing a Stop Motion function block, as described later in this chapter. This stops
any motion on the channel while leaving the channel active.

•

Disabling the channel by setting its enable output bit to 0. No motion functions will
operate on the channel while it is disabled.

CAUTION

To avoid abrupt starting and stopping of motion, the ratio of Velocity/Acceleration or
Velocity/Deceleration must

be ≥ 0.1. For details,

refer to page 374.

Inputs to the Blending Function Block

Because some of the profiles in a Blended Move may not have Ramp Up, At Velocity, and
Ramp Down segments, some parameters may not be used.

Enable

The Enable input provides power flow to the function block.

Axis

A Constant representing the channel (1, 2, 3, 4) on which the Blended Move
will be done.

Execute

Power flow to this input starts execution of the function. Rising edge is
detected to load the parameters and start execution of the function block.

Number of
Profiles

Word variable or Constant representing the number of profiles (1, 2, 3, or
4). Data for each profile must be present in the Motion Parameters
references (below).

Axis
Direction
Input

Boolean variable (%I, Q, M, G, T) or a Constant specifying the axis direction.
0 = Clockwise (CW), 1 = Counter-Clockwise (CW). The actual direction
depends on the field connections and drive settings.

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Motion
Parameter
s

Starting address of 32-word reference location in AI, AQ, or R memory that
will be used for the Motion Parameters of each profile. Acceleration,

deceleration and velocity are specified in the channel’s configured units.

Words 1, 2

Profile 1 acceleration, from 10 to 1,000,000 for channels
1, 2, and 3; 90 to 1,000,000 for channel 4

Words 3, 4

Profile 1 deceleration, from 10 to 1,000,000 for channels
1, 2, and 3; 90 to 1,000,000 for channel 4

Words 5, 6

Profile 1 velocity, from 15 to 65,000

Words 7, 8

Real value. Distance in user units for profile 1

Words 9 to 16 Profile 2 acceleration, deceleration, velocity, and

distance, as above for Profile 1

Words 17 to
24

Profile 3 acceleration, deceleration, velocity, and
distance, as above for Profile 1

Words 25 to
32

Profile 4 acceleration, deceleration, velocity, and
distance, as above for Profile 1

Outputs of the Blended Moves Function Block

Enable
Output

Power flow output, passes power flow when it receives power flow from
the Enable input.

Axis
Direction
Output

Boolean variable (Q0005 to Q0024). The Micro PLC output point for which
direction is to be set. 0 = clockwise, 1 = counterclockwise. The application
program should not override the direction output during the motion
operation.

Done

Boolean variable (%I, Q, M, G, T) for the Blending completion status. Goes
to 1 or passes power flow when motion is complete. If the Execute input is
a pulse, rather than continuously on, Done remains 1/on for one scan after
motion completes.

Active

Boolean variable (%I, Q, M, G, T). Set to 1 when motion starts on the
channel. Resets to 0 when motion stops.

Error

Boolean variable (%I, Q, M, G, T). Set to 1 if an error has occurred within
function block. See Error ID below.

Error ID

Word variable (%AI, AQ, R). If Error (ER) =1, this is an Error ID. If Warning
(WR) =1, this is the Warning ID. See the list of error definitions on page
371.

Warning

Optional parameter. Boolean variable (%I, Q, M, G, T). Set to 1 when a
warning has occurred. See Error ID above. Warning is generated when the
same motion is triggered again while it is already in progress.

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19.6

Stopping Motion on an Axis

As mentioned for the individual functions, motion can be stopped by:

•

Disabling the channel by setting its High-Speed Counter enable output bit to 0. This
stops all motion functions on the channel.

•

Executing a Stop Motion function block as described below. This stops any motion
on the channel while leaving the channel active.

19.6.1

Stop Motion Function Block

The application program can use the Stop Motion function block to stop any motion
operation:

Figure 226

When the Execute input receives power flow and the Enable input is high, and there is no
stop motion instance on the axis, the parameters are loaded. If the parameters are valid, a
low to high transition on the Execute input starts execution, stops the axis with the specified
input deceleration value (or immediately) based on the value of Stop mode input, and sets
the Active output to 1. The Done output goes to 1 when the axis stops and the Active output
returns to 0. Done remains high until the Execute input transitions low. If Execute is a pulse,
Done remains high for one scan after the axis stops (Active becomes low). If the parameters
are not valid, an error code is generated, and the function does not start.

To execute the function block with different parameters, remove power flow from the
Enable and Execute inputs. Then, change the parameters. The function block will execute
with the new parameters when power flow is applied to the Enable input and a low to high
transition occurs on the Execute input.

Execute input transitions are not monitored unless the Enable input is receiving power flow.
When the Enable input receives power flow, the Execute input is monitored for a change in
status from the previous logic scan. Therefore, Enable and Execute should not be made low
in the same scan or be made high in the same scan. If both Enable and Execute were set to
low in the same logic scan, the change to the Execute state would not be seen by the Stop

Motion function block because Enable is already low. So although the function block’s

Execute input is low, it still controls the axis and no motion can occur on that axis.

If the Enable input stops receiving power flow while motion is in progress, the function

block’s Done output will not indicate when motion stops. In this case, the application

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program sho

uld monitor the Done output bit (bit 2) at address +0 of the function block’s

assigned Instance data to determine when the motion is completed.

More than One Stop Motion Function Block for an Axis

If the application logic contains more than one Stop Motion function block for an axis, the
state of the Execute input of the last Stop Motion function block in the scan that has positive
power flow determines whether the Stop Motion function block controls motion on the axis.

For example, suppose the logic contains two Stop Motion function blocks for the same axis,
and jogging is running on that axis. Execute is triggered for the first Stop Motion function
block, but the Execute input of the second Stop Motion function block is 0. The first instance
of the Stop Motion function block takes control of the axis and stops the current jogging.
After jogging stops, because the Execute input of second (or last) Stop Motion function
block is still 0, Stop Motion is not controlling the axis and jogging can again be started on
the axis.

CAUTION

To avoid abrupt starting and stopping of motion, the ratio of Velocity/Acceleration or

Velocity/Deceleration must be ≥ 0.1. For

details, refer to page 374.

Inputs to the Stop Motion Function Block

Enable

The Enable input provides power flow to the function block.

Axis

A Constant representing the channel (1, 2, 3, or 4) on which motion will
stop.

Execute

Power flow to this input controls execution of the Function Block.

Stop Mode

Boolean variable (%I, Q, T, M, G) or Constant to control the Stop Mode. 0
= decelerate to stop (normal stop mode). 1 = stop immediately.

Deceleration Optional Dword variable or Constant representing the jogging

deceleration rate, between 10 and 1,000,000 for channels 1, 2, and 3. 90
to 1,000,000 for channel 4.

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Outputs from the Stop Motion Block

Enable output Boolean power flow output, passes power flow when it receives power

flow from the Enable input.

Done

Boolean variable (%I, Q, M, G, T). Goes to 1 when motion is has stopped.
If the Execute input is a pulse, rather than continuously on, Done
remains 1/on for one scan.

Active

Boolean variable (%I, Q, M, G, T) for the function status. 1 = Stopping in
progress.

Error

Boolean variable (%I, Q, M, G, T). Set to 1 if an error has occurred within
function block. See Error ID below.

Error ID

Word variable (%AI, AQ, R). If Error (ER) =1, this is an Error ID. If Warning
(WR) =1, this is the Warning ID . See the list of error definitions on page
374.

Warning

19.6.2

Example Program Logic for Stop Motion

Figure 227

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Chapter 20:

Fault Handling

This chapter discusses how the Micro PLC handles system faults.

20.1

Faults and Fault Handling

A fault is a failure or condition that can affect the operation and performance of the system.
A fault may impair the ability of the PLC to control a machine or process.

20.1.1

Fault Handling

When a fault is detected, the PLC processes the fault and sets the corresponding system

bit(s) (See ‘System Bit Reference Table’). The PLC logs the fault into a fault table. There are

two different fault tables:

•

The I/O Fault Table

•

The PLC Fault Table

Contents of the fault tables can be monitored and cleared from the programmer.

20.1.2

Classes of Faults

The Micro PLC detects several classes of faults, including:

•

Internal Failures

—

Non-responding circuit boards

—

Memory checksum errors

•

External Failures

—

Sequence fault

•

Operational Failures

—

Communication failures

—

Configuration failures

—

Password access failures

20.2

System Responses to Faults

Some faults can be tolerated, while others require that the PLC shut down. I/O failures may
be tolerated by the PLC, but not be acceptable for the application. Operational failures can
normally be tolerated.

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20.2.1

Fault Actions

The PLC categorizes different groups of faults as:

•

Informational

•

Diagnostic

•

Fatal

The PLC logs all faults in the appropriate fault table. For diagnostic and fatal faults, the PLC
sets any associated diagnostic variables. The following table lists the fault action, associated
fault table, and diagnostic variables for different types of faults. In addition, if the fault is a
fatal fault, the PLC halts the system (STOP/FAULTED mode) to prevent possible damage to
the equipment, or personal injury.

Fault Group

Action

Fault Table

Diagnostic Variables

System Configuration
Mismatch

Fatal

PLC Fault Table

sy_flt(%SC10) any_flt(%SC9) sy_pres(%SC12) cfg_mm(%SA9)

Expansion Unit
Configuration
Mismatch

Fatal

PLC Fault Table

sy_flt(%SC10) any_flt(%SC9) sy_pres(%SC12) cfg_mm(%SA9)

PLC CPU Hardware
Failure

Fatal

PLC Fault Table

sy_flt(%SC10) any_flt(%SC9) sy_pres(%SC12) hrd_cpu(%SA10)

PLC Software Failure
(see below)

Fatal

PLC Fault Table

sy_flt(%SC10) any_flt(%SC9) sy_pres(%SC12) sft_cpu(%SB13)

PLC Store Failure (see
below)

Fatal

PLC Fault Table

sy_flt(%SC10) any_flt(%SC9) sy_pres(%SC12) stor_er(%SB14)

Program Checksum
Failure

Fatal

PLC Fault Table

sy_flt(%SC10) any_flt(%SC9) sy_pres(%SC12) pb_sum(%SA1)

No User Program on
Power-up

Diagnostic PLC Fault Table

sy_flt(%SC10) any_flt(%SC9) no_prog(%SB9)

Corrupted User RAM

Fatal

PLC Fault Table

sy_flt(%SC10) any_flt(%SC9) sy_pres(%SC12) bad_ram(%SB10)

Unknown PLC Fault

Fatal

PLC Fault Table

sy_flt(%SC10) any_flt(%SC9) sy_pres(%SC12)

Unknown I/O Fault

Fatal

I/O Fault Table

io_flt(%SC11) any_flt(%SC9) io_pres(%SC13)

PLC Fault Table Full

Diagnostic -

sy_flt(%SC10)

I/O Fault Table Full

Diagnostic -

io_full(%S10)

Application Fault

Diagnostic PLC Fault Table

sy_flt(%SC10) any_flt(%SC9) sy_pres(%SC12) apl_flt(%SA3)

Password Access
Failure

Diagnostic PLC Fault Table

sy_flt(%SC10) any_flt(%SC9) sy_pres(%SC12) bad_pwd(%SB11)

Constant Sweep Time
Exceeded

Diagnostic PLC Fault Table

sy_flt(%SC10) any_flt(%SC9) sy_pres(%SC12) ov_swp(%SA2)

Loss of Expansion Unit Diagnostic I/O Fault Table

io_flt(%SC11) any_flt(%SC9) io_pres(%SC13) los_iom(%SA14)

Addition of Expansion
Unit

Diagnostic I/O Fault Table

io_flt(%SC11) any_flt(%SC9) io_pres(%SC13) add_iom(%SA19)

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PLC
Software
Failure

If a PLC Software Failure is logged, the PLC immediately goes into Error
Sweep mode. The only way to clear this condition is to cycle power.

PLC

Store

Failure

A sequence store is the storage of program blocks and other data
preceded by the special Start-of-Sequence command and ending with the
End-of-Sequence command. If communications with the programmer are
interrupted or if any other failure terminates the download, the PLC Store
Failure fault is logged. As long as this fault is present in the system, the PLC
will not transition to Run mode.

20.3

Fault References

The PLC defines a set of special fault references that can be included in the application
program to check for fault conditions, and allow appropriate action to be taken should one
of these faults occur.

These special fault references remain set until the PLC is cleared or until the application
program clears the fault.

20.3.1

Example Program Logic for Fault References

This example ladder logic shows how the fault reference  ov_swp can be programmed to
check for an over-sweep condition, then cleared. In this example, an indicator light_01 is
turned on to alert the operator that an over-sweep has occurred. After fixing any problem in
the  application,  the  operator  presses  a  pushbutton.  This  causes  program  input  %I0035
contact to pass power flow to the ov_swp  reference, which clears the associated memory
location.

Figure 228

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Chapter 21:

Elements of an Application
Program

This chapter provides basic information about the application program.

•

Structure of an application program

•

Subroutines

•

Program languages

•

Instruction set

21.1

Structure of an Application Program

The application program consists of all the logic needed to control the operation of the
Nano or Micro PLC.

Application programs are created using the programming software and transferred to the
PLC. Programs are stored in non-volatile memory.

During the CPU Sweep (described in Chapter 17:), the Micro PLC reads input data and stores
the data in its configured input memory locations. The Micro PLC then executes the entire
application program once, utilizing this fresh input data. Executing the application program
creates new output data that is placed in the configured output memory locations.

After completing the end of the application program, the CPU provides the output data to
the output points.

Figure 229

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21.2

Subroutines

The program can consist of one Main program that executes completely during each CPU
sweep.

Figure 230

Or a program can be divided into subroutines. The maximum size of a main program block
or subroutine block is 16K bytes. A Nano PLC application program can include up to 8
subroutine declarations. A Micro PLC application program can include up to 64 subroutine
declarations.

Subroutines can simplify programming and reduce the overall amount of logic. Each
subroutine can be called as needed. The main program might serve primarily to sequence
the subroutine blocks.

Figure 231

A subroutine block can be called many times as the program executes. Logic that should be
repeated can be placed in a subroutine block, reducing total program size.

Figure 232

In addition to being called from the program, subroutine blocks can also be called by other
subroutine blocks. A subroutine block can even call itself.

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