Specifications
Section
1-3
39
Item
Description
Execu-
tion of
function
blocks
Load rate
The "load rate" refers to the ratio between the actually applied execution time and preset
operation cycle.
The maximum value and current value are displayed for each operation cycle group on the
CX-Process Tool.
A load rate of 60% or less is required in all operation cycle groups.
When the load rate continuously exceeds 70% for ten times, the load rate automatically
changes to the next longer operation cycle. (This is called the "automatic operation cycle
switching function.")
Note: Operation of the Loop Control Unit is automatically stopped when the operation
cycle of all function blocks is set to two seconds, and the load rate continuously
exceeds 70% for ten times.
External I/O refresh cycle
The time from external input of analog signals up to external output of analog signals on a
single control loop depends on the function block’s operation cycle and the CPU Unit’s
cycle time. Generally, the external I/O refresh cycle is obtained by adding "approximately 1
to 5 times the CPU Unit’s cycle time" to "approximately 1 to 3 times the operation cycles of
the Loop Control Unit’s function blocks." (For a detailed description of how to calculate the
external I/O refresh cycle, see 3-2 Description of Operations.)
Number of
control loops
Max. 32 loops (Max. 32 ON/OFF control, Basic PID blocks and Advanced PID blocks and
other control blocks can be used simultaneously.)
Note: The maximum number of control loops is restricted by the operation cycle. In most
cases (when there is no Step Ladder Program), the maximum number of control
loops is 32 loops at operation cycles of 2, 1 and 0.5 seconds; 16 loops at an
operation cycle of 0.2 seconds; and 8 loops at an operation cycle of 0.1 seconds.
Number of
operations for
process
(excluding
control)
Max. 250 blocks
Internal
Operation
Sequence
control
Max. 100 blocks per unit and total max. 4000 commands per unit
Divisable to max. 100 commands per block and max. 100 steps per block (max. 100
commands per step)
PID control
PID with two degrees of freedom
Control
method
Possible control
type
combinations
Basic PID control, cascade control, feedforward control, sample PI control, dead time
compensation, PID control with differential gap, override control, program control, time-
proportional control and other control types can be achieved by combining function blocks.
Integrated into
PID block
4 PV alarms (high/high limit, high limit, low limit, low/low limit) per PID block, 1 deviation
alarm
Alarm
Alarm block
High/Low Alarm block, Deviation Alarm block
Internal analog signal
Min. -320.00% to max. +320.00%
Scaling of the engineering units depends on the CX-Process Tool (sold separately).
Monitoring/setting by engineering units depends on CX-Process Monitor (sold separately).
Operating status monitor
method
Executed by CX-Process Monitor (sold separately)
External
I/O
External I/O
signals
By data exchange with Analog I/O Unit via
the Field Terminal block
External contact
I/O signals
By data exchange with Basic I/O Unit via
the Field Terminal block
Total number of I/O points:
(max. 8 points on Analog Input Unit or Analog
Output Unit, or max. 96 points on Basic I/O
Unit) x 80 blocks
CPU Unit analog
data I/O
By data exchange with CPU Unit I/O
memory via the CPU Unit Terminal Block
CPU Unit contact
data I/O
By data exchange with CPU Unit I/O
memory via the CPU Unit Terminal Block
Total number of I/O points:
(8 words or 128 contacts on CPU Unit) x 16
blocks
CPU Unit analog
data I/O
By data exchange with CPU Unit I/O
memory via the Expanded CPU Unit
Terminal Block (direct I/O with other
function blocks, and I/O of parameter
ITEMs on other function blocks possible)
CPU Unit contact
data I/O
By data exchange with CPU Unit I/O
memory via the Expanded CPU Unit
Terminal Block (direct I/O with other
function blocks possible)
Total number of I/O points:
(64 words or 64 contacts on CPU Unit) x 32
blocks
Analog/contact
I/O with SCADA
software
Data transfer between Loop Control Unit
and I/O memory in CPU Unit for Control,
Operation, and External Controller blocks
using Send/Receive All Blocks.
Total number of I/O points:
313 blocks max. x 20 words/block = 6,280
words allocated in CPU