Nidec SM-Applications Series - Communications; EIA-RS485 Serial Communications Port

SM-Applications Modules & Motion Processors User Guide 69
Issue Number: 4
Safety
Information
Introduction Installation
Getting
Started
Parameters
DPL
Programming
Communications
Freeze and
Marker
CTSync
IInter-option
Synchronization
Diagnostics
Migration
Guide
Quick
Reference
Index
6 Communications
6.1 EIA-RS485 Serial Communications Port
Please see Features section on pages 8, 9 & 10 for availability on your module.
The Second Processor may come with a EIA-RS485 serial communications port on-
board. Refer to section 3 Installation on page 14 for information on the hardware
connections and wiring or the drive manual for Digitax ST Plus.
This port supports a number of built-in protocols: CT-ANSI slave, Modbus RTU in
master and slave modes, Modbus ASCII in master and slave modes and 3 user modes.
Both two and four wire configurations are possible
If an invalid or unsupported mode is selected, the mode will be defaulted back to 1 (4-
wire CT-ANSI) and a run-time error 49 may occur.
The baud-rate is specified in Pr
81.07.
The address of this unit is specified in Pr
81.05.
6.1.1 CT-ANSI
The Second Processor supports the ANSIx3.28 protocol.
All drive parameters as well as Second Processor parameters can be accessed via the
EIA-RS485 port on the module.
6.1.1.1 Reading a parameter
The following tables show the message constructs for reading a parameter.
The CT-ANSI protocol supports reading and writing of full 32-bit values. The UD70
product for Unidrive 1 does not support such large values.
NOTE
Table 6-1 Master request
Character Description
EOT End of transmission (Ctrl & D)
A1
Second Processor address: 1
st
digit
A1
Second Processor address: 1
st
digit
A2
Second Processor address: 2
nd
digit
A2
Second Processor address: 2
nd
digit
M1
Menu number: 1
st
digit
M2
Menu number: 2
nd
digit
P1
Parameter number: 1
st
digit
P2
Parameter number: 2
nd
digit
ENQ Enquiry (Ctrl & E)
Table 6-2 Slave response (if request was correct and parameter exists)
Character Description
STX Start of text (Ctrl & B)
M1
Menu number: 1
st
digit
M2
Menu number: 2
nd
digit
P1
Parameter number: 1
st
digit
P2
Parameter number: 2
nd
digit