Ulvac MBD-D, Instruction Manual

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CRYO-METER MBD-D Instruction Manual
ULVAC CRYOGENICS INCORPORATED 9
(2) Set Terminating Resistor
The last unit of connected MBD-D requires the terminating resistor settings. Turn ON the
switch <1> of <Resistor> to activate, and turn it OFF to inactivate the terminating resistor.
(3) Set Address
Press and hold the <SETTING> circle button for longer than 3 seconds to start settings menu.
You can change the address of the MBD-D by pressing the triangle button. Digits can be
changed by pressing the circle button shortly. After settings are completed, press and hold
the circle button for longer than 3 seconds to close the settings menu. Set the same figures
to the address as C30S. The allowable figures are from 1 to 250. Note that communication
may fail if an address is duplicated among multiple units of MBD-Ds.
5.4 Direct Communication with MBD-D
The procedure to transmit data directly without C30S is as follows.
Direct Communication Settings
From the rear of the MBD-D, connect the pin No.4 of RS485 and D+ (or RX(+) and TX(+)) of
RS485 of the desired device, and connect the pin No.5 and D- (or RX(-) and TX(-)). After the
connection has been made, check the transmission speed, terminating resistor, and address
as described above. Refer to Table 3-1 for connector pin allocation.
After checking them, set the transmission speed consistent at the target device..
Other settings are as follows;
Data Bit : 8 Bit
Stop Bit : 1 Bit
Parity : None
5.5 Modbus Protocol
The MBD-D uses Modbus protocol for communication.
For detailed information on Modbus, visit the web site of Modbus.org.
The Modbus protocol message is composed as follows;
Device Address Function Code Data Error Check (CRC)

Device Address : The address of each MBD-D as a slave. Set different addresses to all the
MBD-D units to be connected. If there is another MBD-D with the same address, it may
invite communication trouble.