CDN36X User Manual
revision 1.30
Make sure
Serial Transmit Object
instances 2-8 are disabled, since only Instance 1 is used in this
application. The gateway expects to receive 67 output bytes from the DeviceNet scanner in the
I/O Command Message. The
I/O Produce Size
is 67, with the data organized as follows:
[ Transmit Toggle bits 0000000x ] [ Receive Acknowledge bits ] [ Instance 1 Short_String printer data ]
1
byte
1
byte
65
bytes
The gateway is now configured to receive ASCII text messages up to 64 characters in length and
send them to the serial printer. The DeviceNet scanner will always send 67 outputs in the I/O
Command Message, even if the text message is shorter than 64 characters. The gateway uses the
Short_String length byte to determine the number of valid characters to be transmitted.
Transmit synchronization must be used by the application. The application toggles the Instance
1
Transmit Toggle
bit in the I/O Command Message when it sends a new text message, and
monitors the Instance 1
Transmit Acknowledge
bit returned in the I/O Response Message. When
the
Transmit Acknowledge
bit equals the
Transmit Toggle
bit, then the application can send the
next text message.
The
I/O Consume Size
can be verified by reading the
Serial Stream Object’s I/O
Consume Size
attribute (class 64, instance 1, attribute 21).
MKS Instruments, Inc.
D.I.P. Products Group
87