Allen-Bradley POINT I/O 1734-VHSC24, User Manual, Page: 51 / 64

Publication 1734-UM003A-EN-P - August 2000
Accessing Instantiated Instances 5-3
Assemblies
Available assemblies are:
•
Assembly 101 is produced for a polled connection.
•
Assembly 102 is produced for a Change Of State (COS)
connection.
•
Assemblies 103, 104, 107 and 108 are by Explicit message only.
•
Assemblies 105 and 106 are consumed in a polled connection
(as directed by parameter 4).
Data may be read (get) or written (set) using an Explicit Message. For
example, to read the Present Channel Data, assembly 101
10
(65
16
) can
be requested.
Data is ordered as followed (byte 0 is the least significant byte):
8 bit byte Byte 0
16 bit word Byte 0, byte 1
32 bit long word Byte 0, byte 1, byte 2, byte 3
In this example, assembly 101,
Service Class Instance Attribute
0E (Get) 04 (Assembly) 65 (Present Data) 03 (Data Attribute)
Instances Services Field Bytes
#101 (0x65) Get Present Channel Data 4
Status 2
#102 (0x66) Get Stored Channel Data 4
Status 2
#103 (0x67) Get Present Channel Data 4
Stored Channel Data 4
Status 2
#104 (0x68) Get Programming Error Code 2
#105 (0x69) Set/Get Counter Control 1
Output Control 1
#106 (0x6a) Set/Get PWM Value 2
#107 (0x6b) Set/Get PWM Value 2
Counter Control 1
Output Control 1