CDN36X User Manual
revision 1.30
Serial Transmit Object
The
Serial Transmit Object
receives an output data value from the DeviceNet master in the I/O
Command Message. The object converts the output data into a serial message packet to transmit
out the serial channel. The output data format can be a
Short_String
(byte array, with 1
st
byte =
length), a signed or unsigned integer, or a real number data type. An integer or real number can
be converted into ASCII characters that represent the numerical value before it is transmitted.
String1
and
String2
character strings can be placed before and/or after the converted data in the
message packet, allowing you to build and transmit complex messages. The following examples
show how the
Transmit Serial Object
can be configured to convert a data value into a message
packet.
You can configure up to 8
Serial Transmit Object
Instances, allowing you to transmit up to 8
different serial messages. You can also build complex messages by linking together each
instance’s message packet. The
Serial Transmit Object
sequentially processes the I/O Command
Message output data in order of instance number, starting with Instance 1. Each enabled
instance converts its output data bytes into a message packet that is loaded into the transmit
buffer. The following examples show how the
Serial Transmit Object
Instances create
messages.
Instance Message Packet
String1
Data
String2
String1
String2
0x03 0x41 0x42 0x43
‘ABC’
1)
Output Data Bytes
Short_String, data size = 4.
Use Data Field.
[ 0x41 0x42 0x43 ] = ‘ABC’
Transmitted Message Packet
0x08
‘8’
2)
Output Data Byte
USINT integer, data size = 1,
width = 1, conversion = D.
Use Data Field.
[ 0x08 ]
Æ
‘8’ (0x38)
Transmitted Message Packet
0xFF 0x47
‘VAL = -185 F’
3)
Output Data Bytes
INT integer, data size = 2,
width = 4, conversion = D.
Use String1 Before [ 0x06, ‘VAL = ‘].
Use Data Field.
Use String2 After [0x02, ‘ F’].
[ 0xFF 0x47 ] = -185
Æ
‘-185’
Transmitted Message Packet
Transmitted Message
String1 Before
Data
String2 After
Data
String2 After
Data
String1 After
String2 Before
Instance 1
message packet
Instance 2
message packet
Instance 3
message packet
Instance 4
message packet
MKS Instruments, Inc.
D.I.P. Products Group
17