Controls & Instrumentation Product Manual - Spirax Sarco

Control
Valves
Controllers
Trans. & Sensors
214
Description
The SX77+ is a full featured yet simple to operate process controller
making it suitable for many applications. It is a universal input
controller, which has a number of in-built output options with an
advanced PID algorithm for close control of industrial processes.
The SX77+ is intended for use with our range of control valves,
actuators, positioners and sensors.
Features
Auto-tuning set-up
The controller can automatically select the ‘step response’ or ‘natural
frequency’ method depending on the process variable’s deviation
from the set-point.
Continuous adaptive tuning
The controller’s self-learning, non-intrusive logic constantly
monitors the process and adjusts the PID parameters for optimum
performance.
Universal output
Outputs include – current, voltage, VMD (valve motor drive), relay
and logic voltage.
Dual outputs
The second output can be used for control or for re-transmission of
the process variable or the set-point. For example, two synchronized
mA outputs could be used to operate two split-ranged positioners
with one positioner on each output.
Transmitter power supply
For transmitters requiring 24Vdc, power can be supplied by the
controller.
Serial communications
As standard, RS485 Modbus/Jbus communications capability is
included. The controller can be used either as a master or slave unit.
Also PROFIBUS DP slave capability is included.
Alarms
There are 4 programmable relay outputs for deviation, band and
process alarms with latching, blocking, time delayed and asymmetric
hysteresis adjustment. Two of these alarms are used for VMD output
if this control method is used.
Remote set-point
For cascade control using two controllers working as master and
slave or for remote control of the working set-point.
Multiple set-points
The SX77+ can operate using a local set-point or a remote set-point.
Up to four set-points can be stored.
Configuration software and memory chip
A software tool is available to assist in the configuration and
parameterization. All the data can be saved to a file and stored
on a PC. An optional portable memory chip enables a preset
configuration to be downloaded to the controller or backed up from
the controller.
Approvals
These units are UL and cUL listed and are CE marked.
SX77+
Process Controller
Local regulation may restrict the use of this product below the conditions quoted. Limiting conditions refer to standard connections only.
In the interests of development and improvement of the product, we reserve the right to change the specification.
TI-1-621-US 4.09