User Manual

Watlow Series SD Limit with DeviceNet ■ 5 ■
Table 10. Assembly Object Instance Attributes
Poll Connection
The poll connection allows the master to write set point and
process value in one connection. It also allows the reading of
all process value, set point and alarm status.
Table 11. Static Input – Instance 101 in the Assembly Object (total of 6 bytes)
Byte Parameter and Description Size of Data Range
0 Exception Status Byte
Byte reserved for future use. (Required byte for
Semiconductor-Sig)
USINT Always returns a value of zero.
1-4 Process Value
Actual value of process input
DINT -1999.000 to 9999.000
5 Alarm Status
Indicates when alarm outputs are in alarm condi-
tion.
Breakdown of byte:
bit 0: limit low 1 status
bit 1: limit high 1 status
bit 2: limit or alarm low 2 status
bit 3: limit or alarm high 2 status
USINT For each bit:
(0) None
(1)
Limit / Alarm
Instance # Access Rule Name DeviceNet Data
Type
Description of
Instance
Semantics of
Values
100 Set Poll Output DINT + DINT +
USINT
Poll Output
(PLC to Controller)
See Table 11.
101 Get Poll Input USINT + DINT +
USINT
Poll Input
(i.e. Controller to
PLC)
See Table 12.
Attribute # Access Rule Name DeviceNet Data
Type
Description of
Instance
Semantics of
Values
3 Get Data Array of BYTES See description
below
See description
below
Class Services: GET ATTRIBUTE SINGLE
Instance Services: *SET ATTRIBUTE SINGLE (when
MACID or BAUD RATE in PRG MODE), GET
ATTRIBUTE SINGLE, ALLOCATE M/S CONNECTION
SET, RELEASE M/S CONNECTION SET.
Assembly Object – “Static”
Class Code: 04hex
The Assembly Object binds attributes of multiple objects,
which allows data to or from each object to be sent or
received over a single connection. Assembly objects can be
used to bind input data or output data. The terms “input”
and “output” are defined from the network’s point of view.
An input will produce data on the network and an output
will consume data from the network.
The term “Static” implies: assemblies with member lists
defined by the device profile or by the manufacturer of the
product. The Instance number, number of Members, and
member list are fixed.
Table 9. Assembly Object Revision History
Revision Description
01 Initial Release
02 Class-specific Service Code 4B
and 4C obsolete