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required in the response data field to hold the value of each 32-bit
Axiom Plus register read. The Axiom Plus will not support reads of
more than 512 ModBus 4X registers (256 Axiom Plus 32-bit
registers). Also, any query requesting the reading of a “reserved”
register will be considered to be in error and an exception response
will be returned. Register mapping to 4X reference address space is
done so that it is possible to read all register types (position, velocity,
and torque-limit registers) with a single 03 command for Axiom Plus
registers with id’s from 1 to 8. Axiom Plus registers with id’s greater
than 8 are grouped in contiguous blocks by type, allowing groups of
Axiom Plus registers of a particular type to be read using a single 03
command.
05 Force Single Coil
This command message provides for forcing the logic state of a
single ModBus 0X reference coil. This command can be broadcast,
i.e. sent with the broadcast address such that the commanded
forcing action occurs in multiple slave devices. The Axiom Plus will
only support forcing (setting or resetting of logic state) of PLC
forcing flags. Physical outputs cannot be forced. The normal
response to this command is simply an echo of the query, sent once
the coil logic state has been forced. If the coil addressed for forcing
does not correspond to an existing PLC forcing flag address in the
Axiom Plus, the message will be considered in error and an
exception response will be returned. The absolute maximum
number of coils to be forced that will ever be supported by this
command in the Axiom Plus is 256.
15 Force Multiple Coils
This command message provides for forcing the logic state of single
or multiple ModBus 0X reference coils. This command can be
broadcast, i.e. sent with the broadcast address such that the
commanded forcing action occurs in multiple slave devices. The
Axiom Plus will only support forcing (setting or resetting of logic
state) of PLC forcing flags. Physical outputs cannot be forced. A
normal response contains the slave address, command function
code, starting address, and number of coils forced. If coil addresses
for forcing do not correspond to existing PLC forcing flag addresses
in the Axiom Plus, the message will be considered in error and an
exception response will be returned. The absolute maximum
number of coils forced by a single 15 command that will ever be
supported by the Axiom Plus is 256.
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