Table of Contents
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Overview
The EMX-7510 supports a static mode where user-driven software commands execute
reading/writing data channels on a per port basis. Each port can be programmed for direction and
polarity. The default direction is input and default polarity is normal. Ports also need a voltage
reference before data can be read or written; this voltage is used for pulling up open drain data
lines and setting reference voltage for threshold detection in input path. No voltage should be
applied on data lines before voltage selection and during voltage configuration process. User can
select a voltage from 3.3 V, 5 V, 12 V or 24 V provided on the module or supply a voltage
through front panel connector, to be used as V
lines are floating. There is also an option of configuring a port's voltage setting as either TTL or
Low Voltage emulation. In TTL emulation setting, open drain lines are pulled up to 5 V and have
a sourcing capability of 4 mA, whereas in Low Voltage (LV) option the pull-up voltage is 3.3 V
with 4 mA drive strength.
When doing read and writes, data written to a port set for output updates data on that port, data
written to a port set for input does not have any effect. Data read from a port always reads current
status of data pins (whether driven by card or by user).
When a port's direction is output, data is driven by the DIO on the corresponding channels and no
user voltage should be applied on those channels. When direction is input, data lines are pulled up
to V
CLAMP
zero to V
TTL and LV emulation voltage selection is only applicable when port's direction is output. Input
mode will not be allowed for emulation voltage.
Power on Reset
Power on Reset / Soft Reset of EMX-7510 brings the ports to a default state as in Table 2-3.
Model
EMX-7510
Voltage Configuration
•
When the card is reset, no Voltage will be selected at the ports and data in output registers are
set to FF.
•
A ports output register data is set to FF for any voltage configuration. Only concerned port is
affected.
•
A port's direction is changed to output, when its voltage is set for TTL/LV emulation. Only
concerned port is affected.
Data in output registers is retained if direction is changed. So for example, when an output port
that is driving AA on data lines is made input, all its channels are pulled up so that user data can
be driven but when the direction is changed back to output, AA gets driven, given that polarity and
voltage setting didn't change.
Polarity settings are applicable irrespective of direction. On output channels, changing the polarity
flips the state of data lines and further writes are done according to polarity selection (for example,
if polarity is configured as reversed then writing 1 to a channel writes a 0 to it and vice versa).
Read back of data, whether driven by card when direction is output or driven by user when
EMX-75XX Index
using 100 kΩ resistor and user can drive their data on the channels with a V
.
CLAMP
Direction
Polarity
Input
Normal
T
1-3: R
ABLE
. By default, no voltage is selected and data
CLAMP
Data
0xFF
(Internal Pull up)
ESET CONDITION
www.vtiinstruments.com
range of
IN
Voltage
0V
17
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