Specifications

Setting Up Analog Input and Output Channels
This section covers configuring input and output channels to provide the
measurement values and output characteristics that an algorithm needs to operate.
Configuring
Programmable
Analog SCP
Parameters
This step applies only to programmable Signal Conditioning Plug-Ons such as the
VT1503A Programmable Amplifier/Filter SCP, the VT1505A Current Source SCP,
the VT1518A Resistance Measurement SCP, the VT1510A Sample and Hold SCP
and the VT1511A Transient Strain SCP. See the particular SCP’s User’s manual to
determine the gain, filter cutoff frequency or excitation amplitude selections that it
may provide.
Note The VT1419A only supports these programmable analog SCPs on SCP positions 4
through 7.
Setting SCP Gains An important thing to understand about input amplifier SCPs is that given a fixed
input value at a channel, changes in channel gain do not change the value an
algorithm will receive from that channel. The DSP chip (Digital Signal Processor)
keeps track of SCP gain and range amplifier settings and “calculates” a value that
reflects the signal level at the input terminal. The only time this in not true is when
the SCP gain chosen would cause the output of the SCP amplifier to be too great for
the selected A/D range. As an example, with SCP gain set to 64, an input signal
greater than ±0.25 volts would cause an over-range reading even with the A/D set
to its 16 volt range.
The gain command for SCPs with programmable amplifiers is:
INPut:GAIN <gain>,(@<ch_list>) to select SCP channel gain.
The gain selections provided by the SCP can be assigned to any channel
individually or in groups. Send a separate command for each gain selection. An
example for the VT1503A programmable Amp&Filter SCP:
To set the SCP gain to 8 for channels 40, 44, 46, and 48 through 51 send:
INP:GAIN 8,(@140,144,146,148:151)
To set the SCP gain to 16 for channels 56 through 59 and to 64 for channels 60
through 63 send:
INP:GAIN 16,(@156:159)
INP:GAIN 64,(@160:163)
Programming the VT1419A Multifunction
Plus
Setting Up Analog Input and Output Channels
56 Chapter 3
Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com