Micromod MOD: 1750N Output holder for MOD 30ML - Manual (Page 5)

Output Holder Instructions
PRODUCT DESCRIPTION
SECTION 1
PRODUCT DESCRIPTION
1.1 OVERVIEW
For safe operation some processes require that valve position be maintained above a
closed position even when a controller might be removed for service or replacement. The
1750N Output Holder is capable of identifying a controller’s output fault and to maintain the
last good value to the field control device for safe operation. When the controllers output
signal to the output holder is restored and again valid the output holder returns control of the
field device to the controller. Under normal operation i.e.; the controllers output is good,
the controllers output is passed through the output holder to the field control device
unaffected.
The 1750N functions as an output holder and a manual loader when connected to a MOD
30ML Controller or Modcell Multiloop Processor.
Figure 1 .1. 1750N Output Holder
1.2 FEATURES
ƒ Output held at last value
ƒ Manual control & output display
ƒ Feedback circuit for bumpless transfer
ƒ Compatible with standard MOD
1 -1