Cirrus Logic CobraNet - Manual (Page 29)

CobraNet Programmer’s Reference
Management Interface Variable Reference
DS651PM25
©
Copyright 2006 Cirrus Logic, Inc. 29
6.2 Data Types
6.2.1 DisplayString
A DisplayString is an ASCII string comprised entirely of printable characters.
24-bit HMI: The first word indicates the length of the string in characters. Data is stored
three characters per 24-bit word. Character order is MS, Middle, LS. For
DisplayString
variables, documented Size indicates the largest possible word size of the variable. Size
includes the length field. The maximum allowable characters for a DisplayString variable
is (
Size-1) ×3.
32-bit HMI: The first word indicates the length of the string in characters. Data is stored
four characters per 32-bit word. Character order is MS, MH, ML, LS. For
DisplayString
variables, documented Size indicates the largest possible word size of the variable. Size
includes the length field. The maximum allowable characters for a DisplayString variable
is ( Size-1) ×4.
6.2.2 OID
An SNMP object identifier is the numeric name of an SNMP variable. OIDs are also used
for other purposes including system-unique identifiers.
24-bit HMI: OIDs are presented in their native BER encoding. The first word indicates the
length of the encoding in bytes. Data is stored three octets per 24-bit word. Character
order is MS, Middle, LS. For
OID variables documented Size indicates the largest
possible word size for the variable.
Size includes the length field. The maximum number
of octets for the OID variable encoding is ( Size-1) ×3.
32-bit HMI: OIDs are presented in their native BER encoding. The first word indicates the
length of the encoding in bytes. Data is stored four octets per 32-bit word. Character order
is MS, MH, ML, LS. For
OID variables documented Size indicates the largest possible
word size for the variable. Size includes the length field. The maximum number of octets
for the OID variable encoding is ( Size-1) ×4.
6.2.3 IpAddress
An IpAddress is a 32-bit internet protocol (IP) address.
24-bit HMI: Data is stored in the most-significant 16 bits of 2 consecutive 24-bit words as
shown in
Table 10 . The least-significant 8 bits of each location are read as zero and must
be written as zero.
32-bit HMI: Data is stored in a single 32-bit word as illustrated below.
Table 10. IP address Layout, 24-bit Platforms
MS Middle LS
Word 1 IP address byte 2 IP address byte 1 0
Word 2 IP address byte 4 IP address byte 3 0
Table 11. IP address Layout, 32-bit Platforms
MS MH ML LS
IP address byte 2 IP address byte 1 IP address byte 4 IP address byte 3