VXI VT1422A - Manual (Page 78)

76 Programming the VT1422A & VT1529A/B for Remote Strain Measurement Chapter 3
Remote Strain Channel Addressing
Figure 3-15 shows the relationship between SCP positions and Remote
Channel Addressing through the VT1539A SCP (see Figure 2-1 on page 36
to compare with On-Board Channel Addressing). Not all SCP positions need
to contain VT1539As. If needed, VT1539As can be mixed with other analog
sense, source, and digital I/O SCPs.
Channels measured through Remote Signal Conditioning Units like the
VT1529A/B Remote Strain Conditioning Unit are addressed with five digit
channels specifiers rather than the traditional on-board channel’s three digit
specifier. Both three and five digit specifier start with a "1." This is the SCPI
"card number" digit and is retained in the VT1422A for SCPI compatibility.
The next two digits complete the specification of an on-board channel.
When used in a five digit remote multiplexed channel specifier, the first
three digits mean the same as in the on-board specifier. Digits two and three
specify the VT1539A SCP sense channel that is connected to a particular
Remote Strain Conditioning Unit. Only the first two on-board channels are
ever specified with the VT1539A Remote Channel SCP. So, digits two and
three will specify channels 00, 01, 08, 09, 16, 17, 24, 25, 32, 33, 40, 41, 48,
49, 56, or 57. This allows the VT1422A to address up to sixteen
VT1529A/Bs. Digits four and five specify one of 32 channels on the RSCU
and can range from 00 to 31.
Example channel addresses (shown in SCPI channel list syntax), see
Figure 3-15 also:
Ch 0 on VT1529A/B connected to on-board chan 0 (VT1539A in SCP position 0).
(@10000)
Ch 0 on VT1529A/B connected to on-board chan 1 (VT1539A in SCP position 0).
(@10100)
Ch 24 on VT1529A/B connected to on-board chan 48 (VT1539A in SCP position 6).
(@14824)
Of course, in the Scan List, the channel list syntax allows a range of channels
to be specified. Here are some examples:
channels 0 to 31 on each of the two VT1529A/Bs connected to on-board
channels 0 and 1 (VT1539A in SCP position 0). This is 64 Chs.
(@10000:10131)
channels 0 to 15 on the VT1529A/B connected to on-board channel 24
(VT1539A in SCP position 3).
(@12400:12415)
combined previous two examples into a single scan list to show combining
ranges.
(@10000:10131,12400:12415)
Runtime Remote
Scan Verification
The VT1422A provides a method to verify that remote channels in the scan
list defined in algorithms or with the ROUTe:SEQuence DEFine command
are successfully scanned in each RSCU. See “Runtime Remote
Scan Verification” on page 98, “The Operating Sequence” on page 133 and
“Runtime Remote Scan Verification” on page 187.