Toshiba MDB-100 사용자 설명서

다운로드
페이지 38
 
 6 
 
Programmable Pointer Registers 
32 programmable pointer registers are provided for user definition.  By using these 
registers, frequently-accessed drive parameters that may be scattered throughout the 
register map can be grouped together and accessed with a single holding register 
read or write command. 
 
 
Response Delay Function 
A programmable network response delay function is available which forces the MDB-
100 to wait a certain minimum time before generating network responses to Modbus 
commands.  This function is useful when equipment such as radio modems (which 
require a finite time to switch from receive to transmit mode) are used as Modbus 
network bridges.  
 
 
Network Watchdog 
A network watchdog function is available to detect if communication with the master 
controller has been interrupted.  If an interruption is detected, several different drive 
actions can be programmed to ensure that the process under control can be safely 
and automatically driven to a desired state. 
 
 
Modbus Network Connector 
The network interface is a 3-position pluggable terminal block with the following 
signals provided: 
 
Pin Number 
Function 
Modbus network RS485 “A” terminal 
Modbus network RS485 “B” terminal 
Network shield connection point 
 
No network termination is provided on the MDB-100.  Be sure to install proper RS485 
network termination on the MDB-100 units that exist on the extreme endpoints of the 
network bus.  This can be accomplished by placing a 121
Ω
 (
±
5%), 1/2W resistor 
across the A and B network terminals of those 2 units. 
 
 
Drive Network Connectors 
Uses standard RJ-45 style 8-pin modular connectors.  Any standard category-5 
ethernet cable (found in most electronics and office-supply stores) 5 meters or less in 
length can be used to connect the MDB-100 to the drives. 
 
 
Supported Commands 
The MDB-100 presents and receives drive data via Modbus commands 01 (read coil 
status), 03 (read holding registers), 05 (force single coil), 06 (preset single register) 
and 16 (preset multiple registers).