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SPA-ZC 302
5.4.9.
50
Profibus-DPV1/SPA Gateway
Installation and Commissioning Manual
• Global scaling is done using the decimal place setting.
• Parameter specific scaling is done for analog values in the parameter specific
properties dialog.
To calculate the value on the SPA bus, use the following formula:
SPA_Value
=
To calculate the value on Profibus, use the following formula:
Profibus_Value
The scaling factor is configurable when you select a signal of Indirect SPA message
type and click Edit. The default value is 1.
Scaling must be taken into account also in the Profibus master
application when used in the gateway, otherwise the master will
handle scaled values instead of the real values.
Message priority
SPA Poll messages can be handled as prioritized messages, that is, they are polled
more frequently than other messages. The priority of SPA Poll messages can be
configured individually for each analog/digital input/output or a whole slave can be
prioritized.
Normally, all messages will be polled once every cycle regardless their priority.
Between each normal poll, a prioritized poll can be issued using a priority cycle. The
priority cycle only handles prioritized messages.
Messages can be prioritized as follows:
1. Select a signal and click the Edit button, or double-click on the signal.
2. A signal configuration dialog will pop up, in which you can select the Priority
check-box in the left corner.
3. Click OK. The priority will be indicated in the template signal list with the letter
P directly after the name of the signal. The letter N indicates normal priority,
that is the signal is not prioritized. The default is N.
To prioritize a whole slave, select Slave > Prioritize > On.
It is better to prioritize a group of signals, for example, an entire
slave or all slaves' / single slaves' digital inputs or analog inputs.
Profibus_Value
---------------------------------------------------------------------------------------
Decimal_place
(
×
parameter scaling 10
×
(
=
SPA_Value
parameter scaling
1MRS755014
)
Decimal_place
×
)
10
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