Q:What are the power requirements?
DSA3217 and DSA3207 modules require 28 ± 4 Vdc at 10 VA.
DSA3016 modules are powered by the DSA3016 enclosure
DSA3218 modules with an optional heater require 28 ±4 Vdc at 35
VA.
Q:How do the valves in Scanivalve Modules operate?
All ZOC16, ZOC17, and DSA modules have four way valves for each
sensor. Application of a control pressure causes a piston in each
valve to compress an o-ring, forming an air tight seal. All of
these valves are capable of, and have been tested to, a minimum of
one million operations.
Q:What are control pressures?
Control pressures are used to switch the valves in a module to
one of the standard operating modes: Zero, Operate, Calibrate, and
Isolate. Electronic signals are not required to switch these
valves.
Q:How do the control pressures operate the valves?
Each module requires two or three control pressures to operate
the valves, depending on the valve logic. ZOC16, ZOC17 and all DSA
modules require three pressures. Two of the pressures control the
normal valve modes. The third pressure controls a separate purge
valve.
The different modes of operation are obtained by applying the
control pressures in a logical sequence. Truth Tables may be found
in the appropriate module hardware manual that show the logic
required for proper operation.
Q:Do control pressures have to be applied at all times?
All DSA series, ZOC16, and ZOC17 modules are” normally open”
valves. That is, no control pressure is required to put the module
in the Operate mode. Control pressures are required to switch the
valves to the other modes of operation. The control pressure used
for these modules must be 90 to 120 psi depending on the
pressure range of the module.
Q:Is it possible to minimize the number of control pressures needed?
In some cases, yes. For DSA modules, a single control pressure
may be used for “Zero Calibrations” Also, CTL 1 and CTL 2 may be
applied from the same source to switch the module into the
Calibration mode. ZOC22, ZOC23, and ZOC33 modules must have all
control pressures available.
Q:What quality of air should be used for control pressures?
In order to prevent damage to the valves and sensors, the
control pressures for all modules must be “Instrument Grade”. For
more information, please refer to ISA Specification ISA-S7-3.
Q:I have lost my backup coefficients. What can I do?
Scanivalve Corp keeps a record of the coefficients for each
module generated in the most recent calibration performed at
Scanivalve Corp. These coefficients can be obtained at no charge by
contacting Scanivalve Corp, Product Support Dept.
Q:How often should I calibrate the module?
ZOC modules should be re-calibrated at a six month interval for
the best accuracy. Scanivalve Corp provides a utility program for
customers who can perform their own calibrations. This program is
called PressCal and may be downloaded from this website at no
charge.
Q:How do I address the modules?
Addressing is part of the DSM Series modules, so a user does not
need to interface to the address lines. If a module is not used
with a DSM series module, then the addressing would be a 4 to
6 bit address line depending on the number of sensors in the
module. All address line inputs are pulled up to the +15 Vdc
input.