Specifications

A-10

A LAUER driver

The tasks are listed below in detail:

TASK PRIOR. LENGTH START CRITERION

1. Write keyboard status 8 3 When pressing or releasing a key

2. Reset message bit 7 2 Press CLR for delete behavior 2

3. Write PLC setpoint 6 2..3 Always after changing a setpoint variable and leaving

the entry field

4. Read actual values 5 2..24 *) In priorities 0..2, 6 continuously, otherwise when

display is refreshed

5. Read message bits 4 9 Continuously

6. Send PCS status 4 3 After changes

7. Read LEDs, flashing LEDs,

memory and display

behavior 3 3 Continuously

8. Read command word 3 4**) Continuously (menu selections only if the temporary

buffer is empty)

9. Send time and date 2 3..6 After changes

*) Depends on the number of variables displayed and if the addresses

are adjacent. If the addresses are not adjacent, one header is required

per non-adjacent variable (1 word).

**) Task with 2 headers and one data word each.

ZV,S parameters, PLC scan-time The response time can be optimized via the timeout parameter (PCSPRO/

driver parameter). For an optimal response time a data interchange must

take place with the PCS 830 in each programmable controller cycle. The

PCS adjusts the package length of each package to the PLC scan-time

so that the above-mentioned condition is adhered to as much as possible.

Timing sequence of the data transfer:

1111 2222222222222222 33 44444 55555 6666666666666666 (1111)

• 1111

The PCS assembles a new package. The required time totals 2.5

milliseconds in the online operation and 10 milliseconds in the off-

line operation.

• 2222222222222222222

The package is transferred. The required time depends on the

package length and the baud rate. Since the package length is not

constant, this time can on principle not be determined.

•33

The PCS 830 examines the package on plausibility and signals the

handling PB the readiness for the data interchange.

• 44444

Waiting time, until the handling PB is processed.