Quick Zero Jumper; Scanning; Scanning With An External Trigger; Hardware Trigger - Scanivalve DSA3217-PTP Series Operation And Service Manual

Section 3: Operation

Quick Zero Jumper

In order to perform a zero offset calibration 90-120 psi of
control pressure must be individually applied to the CTL1
and the CTL2 control ports. In order to simplify the pro-
cess, all DSA-PTP modules are shipped with a quick zero
jumper. Installing the quick zero jumper to the 'RTN', 'CTL1'
and 'CTL2' ports allows the internal calibration valves to be
placed into the 'Quick Zero' configuration automatically.
By simply applying 90-120 psi of control pressure to the
'CTL SUPPLY' (or 'CTL' on some DSA3218-PTP modules) and
calling the 'CALZ' command, the DSA-PTP module auto-
matically vents control pressure out of the 'RTN' port and
to the 'CTL1' and 'CTL2' ports.
Figure 3.4 - Quick zero jumper installation

Scanning

Once the DSA-PTP module has been installed, powered up
and allowed to thermally stabilize data can be collected.
There are several configuration variables that effect how
the DSA-PTP module scans and how the data is output.
The scan rate is controlled by two variables: 'period' and
'average' variables, the length of the scan sample is deter-
mined by the 'frames per scan' (FPS) variable and the data
output format is determined by the 'format' variable. The
DSA-PTP can be configured for 'free run' mode where after
the 'SCAN' command is send the DSA-PTP module will scan
continuously until the frames per scan (FPS) term is met, or
it can be triggered to scan and output data upon receipt of
a scan trigger (either external or a software trigger). The
following is a list of commands that effect how the DSA-PTP
collects data.
AVG
BIN
CVTUNIT
EU
FORMAT
FPS
More information on all of these configuration variables
can be found in "Section 5: Software" on page 20.
To initiate scanning, simply send the command: 'SCAN'. If a
scan trigger is not being used, data will begin to be output
from the DSA-PTP module over the Ethernet connection.
This data can be collected and recorded using one of the
described in "Client/Host Options" on page 12. If a scan
trigger is being used, after the 'SCAN' command is sent
one frame of data will be output each time a scan trigger is
received.

Scanning With An External Trigger

The DSA-PTP module can be triggered to scan with either a
hardware or a software trigger.

Hardware Trigger

The external trigger input is optically isolated to prevent
grounding problems. It is a TTL level, edge sensing device.
It requires a
accept voltages as high as 15Vdc. The external trigger will
only be active if the XSCANTRIG variable
a 'SCAN' command is issued through the Ethernet con-
nection, the module enters the scan mode and waits for a
trigger. This module will return an averaged frame of data
for each trigger pulse received. This will continue until the
Frames Per Scan (FPS) term is met or until a 'STOP' com-
mand is issued. Trigger pulses are received through pins
1 (+Trig) and 2 (-Trig) of the 'Serial Communications/Trig-
ger' connector on the front of the DSA-PTP module. More
information on the 'Serial Communications/Trigger' con-
nection can be found in "Serial Communications" on page
11.

Software Trigger

The software trigger will only be active if the software
variable XSCANTRIG is set to 1. When a SCAN command is
issued through the Ethernet connection, the module will
PAGE
enter the SCAN mode and wait for a trigger. An averaged
PERIOD
frame of data will be output as soon as the TRIG command
TIME
or a <TAB> character (9 HEX or Control I) is received. Data
UNITSCAN
will be output with each successive trigger command. This
XSCANTRIG
will continue until the Frames Per Scan (FPS) variable value
ZC
is met, or until a STOP command is issued.
14
14
minimum signal of 4.5Vdc @ 6.5mA. It will
Figure 3.5 - Trigger wiring
DSA3200-PTP
is set to 1. When