UD70/MD29 Installation Guide
8
Issue Number: 3
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2.6
I/O Box Port Connections (MD29 Only)
The I/O Box port is marked “PL2” and is only available on the MD29. The terminal
connections are shown in the table below. Operation of this port is automatic, and
no configuration is necessary.
To use the I/O Box with UD70 or MD29AN, connect it to the RS485 port, and
select Mode 10 communications.
2.7
Digital I/O Connections
The RS485 connector has 2 TTL digital inputs and 1 TTL digital output. They are
used in conjunction with the Timer/Counter unit. (For further details, refer to the
User guide for the UD70 or MD29.)
The 0VSC is isolated from the Unidrive or Mentor II 0V, and should not be used
as the reference 0V for the TTL digital inputs and output.
If a digital input is open-circuit or connected to +5V, this will be read by #86.01
(input 0) or #86.02 (input 1) as logic 0. These parameters will change to logic 1
when the inputs are connected to 0V Digital on pin 9.
The digital output will give +5V when #86.03 is set to logic 0, and 0V when set to
logic 1. The digital output is rated to a maximum of 15mA. The maximum length of
cable that should be connected to these terminals is 0.5 metres, so buffering will be
required for longer lengths of cable, and for interfacing to different logic levels.
The Digital inputs and output must be connected to 0V Digital (pin 9), NOT
OVSC (pin 1). The inputs and output will not work properly if connected to
OVSC, as pin 1 is isolated from the Drive. Noise generated along the screen
of the serial communications cable may cause spurious operation, and
damage to the UD70 or MD29 may result.
Pin
Function
Description
1
0V
0V
0V
2
TxB
Tx
Transmit line
3
/TxA
/Tx
Inverted Transmit line
4
RxB
Rx
Receive line
5
/RxA
/Rx
Inverted Receive line
NOTE
NOTE
NOTE
