Rockwell Automation RECOMM-485 RS485 DFI Communications Module - Manual (Page 62)

Glossary-4 RS485 DF1 Communications Module
Type 0/Type 1/Type 2 Control - When transmitting I/O, the module
can use different types of messages for control. The Type 0, Type 1,
Type 2 control events help Reliance Electric personnel identify the
type of message that a module is using.
transaction number (TNS) - A two-byte field in a DF1 message
packet that is used in combination with the SRC (source node of the
message) and CMD (command code) bytes to uniquely identify
every message packet. The TNS typically increments each time a
new DF1 message is sent. The reply message will contain the same
TNS value.
VS Utilities software - A Windows-based software tool for
monitoring and configuring Reliance Electric products and modules.
VS Utilities can be used to configure the RS485 DF1 module and
SP600 drives.
zero data - When communications are disrupted (for example, a
cable is disconnected), the module and drive can respond with zero
data. Zero data results in the drive receiving zero as values for
command data. If the drive was running and using the reference
from the module, it will stay running but at zero reference.