Data Hold Time - Pepperl+Fuchs IC-KP-B7-V95 Manual

IC-KP-B7-V95
Commands
The advantage of this procedure is that only a few data bytes are transferred via
the bus. Ident commands are transferred as the ident system as explicit
commands. A new ident response can be read as soon as the value on the reply
counter changes.
7.1.11

Data hold time

All responses from the device are present in the input field for a specific time.
Make sure that the controller reads all responses before they are overwritten by a
new response. The data hold time indicates how long an IDENT telegram of this
kind remains in the input field. The data hold time can be adjusted via the display
or the boot-up object (see chapter 12.1). Values between 0 and 2.55 seconds can
be preset in 10 ms increments. The default value is 100 ms. Make sure that the
data hold time is greater than the maximum cycle time of the whole system
(including data storage to the PLC). However, the data hold time should not be
much longer than necessary for the following reasons:
1. The reaction time of the device will increase if several responses arrive in
2. The maximum possible number of response telegrams per time unit de-
7.2 Command Execution
The controller initiates an identification command. If the data has changed since
the last read-out, the control interface executes the new command If the control
interface is scheduled to execute a command a number of times, the toggle bit
must be inverted. Only then does the device detect that the command has to be
executed again.
If the control interface detects a new command, it sets the status in the input field
to FFh. The reply counter value increases by 1. The status is displayed () after the
control interface has executed the commands.
The toggle bit of the response is the same as the toggle bit of the command.
When new data becomes available, the previous data is overwritten. The reply
counter value increases by 1. In the event of an overflow, the reply counter is reset
to its start value (01h).
New commands may only be sent to an output field after the response from the
previous command is read.
For an overview of supported commands, .
quick succession.
creases when the data hold time is increased. A memory overflow may oc-
cur. The State LED then flashes green.
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