U. S. Food and Drug Administration
Center for Food Safety and Applied Nutrition
FDA Prime Connection

M-b-319 - Programmable Logic Controller System, etc.
 
 
HHS:PHS:FDA:CFSAN:OC:OFP:MSB
 
                                        200 C Street, S.W.
                                        Washington, DC  20204
 
                                        M-b-319
 
                                        May 1, 1993
 
 
TO:          All Regional Food and Drug Directors
             Attn:  Regional Milk Specialists
 
FROM:        Milk Safety Branch (HFS-626)
 
SUBJECT:     Programmable Logic Controller System for Flow Diversion
             Devices from Custom Control Products, Inc.  (Models 5055P,
             5057P, 5065P, 5067P, 5075P, 5077P)
 
 
FDA has completed the review of a proposed control panel system for flow
diversion devices submitted by Custom Control Products, Inc., Racine,
Wisconsin.  The firm proposes to enhance the previously reviewed
programmable logic controller (Allen Bradley SLC 100) which can currently
be used with all approved flow diversion devices (M-b-313 and M-b-313
Supplement 1).  The enhanced system would be based on the Allen Bradley
SLC 500.  The different model numbers indicated the type of enclosure and
whether or not solenoids are included with this controller (for use with or
without valves without built in solenoids).  Stainless steel enclosures are
model numbers 5055P (without solenoids) or 5057P (with solenoids).
Fiberglass with clear front enclosures are model numbers 5065P (without
solenoids) or 5067P (with solenoids).  The all fiberglass enclosures are
model numbers 5077P (without solenoids) or 5075P (with solenoids).  Both
fiberglass enclosures are designed for installation inside a larger stainless
steel cabinet or control area.
 
When the Allen Bradley SLC 500 is programmed as shown in the attached
ladder logic diagrams, the system complies with the intent of the Grade
"A" Pasteurized Milk Ordinance and Coded Memo M-I-88-11 regarding the
use of computerized systems for public health controls on HTST
pasteurizers.  The hard-wiring to the input board of the control system will
vary slightly depending on which approved flow diversion device is used
with the SLC 500.  Input hard wiring for all FDA reviewed flow diversion
devices required for this control system is also attached to this
memorandum.  The cognizant health authority shall retain a copy of these
ladder logic diagrams and the hard-wiring to the input board for the
appropriate flow diversion device for the office record.
 
Any flow diversion device utilizing the Custom Controls Products, Inc.
system shall pass all tests in the Grade "A" Pasteurized Milk Ordinance for
dual-stem flow diversion devices.  With respect to the requirements of Item
17 in the Coded Memo M-I-88-11, the device panel box with the solenoids
and the SLC 500 will have provision for an inspector's seal.  In addition,
the SLC 500 will have a plastic plate with provision for an inspector's seal
which denies access to the programming port and EEPROM memory card.
The EEPROM memory card supplied by the firm has been permanently
modified so that it cannot be reprogrammed.  Finally the firm will place its
own trademark on the inside of each EEPROM memory card.  If the
cognizant health authority has any questions concerning the program in the
SLC 500, the memory card may be pulled from the SLC 500 to check for
distinguishing trademark.
 
The enclosed electrical drawings are from Custom Control Products, Inc.
and the ladderline logic is provided by the All-Bradley Company.  Also
enclosed is a permission to duplicate both documents for official regulatory
use.
 
States desiring further information or copies of the literature enclosed may
contact:
 
                         Per-Olof Andersson
                    Custom Control Products, Inc.
                      1300 North Memorial Drive
                      Racine, Wisconsin  53404
                           (414) 637-9225
 
Sufficient copies of this memorandum are enclosed for distribution to state
milk control agencies and State Milk Sanitation rating Officers in your
region/district.
 
FDA's review of this dairy equipment and our finding that they comply with
the applicable construction criteria of the Grade "A" Pasteurized Milk
Ordinance does not constitute agency endorsement or approval of the dairy
equipment and any representation on a label or in any printed literature that
they are "FDA approved" would be false.
 
 
 
                                        Steven T. Sims
                                        Senior Milk Sanitation Officer
 
Attachments