After researching several different suppliers, the manufacturer
selected St. Louis, MO, U.S.-based Watlow
to provide a communication solution that is compliant with
the NAFEM (North American Association of Food Equipment Manufacturers)
Data Protocol, which was just finalized in May. Specifically,
the two companies are working closely together to develop
an interface that will connect Hobart foodservice equipment
with an open, wired, or wireless network.
issue: September 2003 APPLIANCE Magazine
Electronic Controls and Embedded Systems
The Commercial Connection
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by Lisa Bonnema, Managing Editor
In May 2003, Hobart Corporation (Troy, OH, U.S.) decided to take its foodservice equipment to the next level by adding communication capabilities.
To start, Hobart had to decide how it wanted to add the
connectivity. According to Rick Cartwright, manager of Electrical
Engineering and Advanced Development at Hobart, there are
several ways a manufacturer can make its products NAFEM compliant.
"One way is a bolt-on solution," he explains. "Suppose you're
a manufacturer of equipment that incorporates very little
electronic support or intelligence on board. You might buy
a bolt-on solution that will give you the ability to support
the protocol. You would attach this black box outside your
machine, and it will have sensors and probes that attach to
the target equipment, and provide data from your equipment
to the network, and, of course, back to the house computer
or some other host."
blast chiller is now NAFEM-compliant after implementing
On-Line Kitchen Gateway.
Hobart, however, chose another option. Because most of its
appliances have advanced electronic controls, sensors for
monitoring data points, and some communication capabilities
already built in, it is using a gateway device from Watlow.
"This is an oversimplification, but think of a gateway as
a protocol converter," explains Mr. Cartwright. "It converts
data that is communicated from the Hobart control and makes
it available on the network using the NAFEM protocol. It made
sense for us to use a gateway because we already have all
this communication in the system, and it's a fast and easy
way to get into the market."
Specifically, Watlow is providing Hobart with its On-Line
Kitchen Gateway. According to Leon McNutt, R&D manager of
Control Technologies at Watlow, the gateway can interface
with any piece of food equipment that has MODBUS RTU protocol
connectivity. "The On-Line Kitchen Gateway uses a 32-bit microprocessor
with FLASH memory, RS485 communication bus driver, real-time
clock, and an Ethernet MAC PHY chip set to provide the connectivity
at both the equipment and network sides and to provide the
processing logic to perform the required functionality that
NAFEM has proscribed for compliance devices," he says.
"Hobart's controller will provide the monitored data information
to its MODBUS RTU interface, and the On-Line Kitchen Gateway
will poll this interface and map the data into the NAFEM Data
Protocol Objects defined by the MIBs [Management Information
Base], thereby making this monitored data available to the
kitchen network," Mr. McNutt continues.
The gateway is also capable of talking to up to eight pieces
of equipment and can then tie all of them to the Ethernet
bus. "So if you have a bank of eight refrigerators lined up
relatively close together, you could tie all eight of these
into one of these NAFEM gateways, and it will connect to your
house computer or to the Internet," notes Mr. Cartwright of
To fully enable its equipment, Hobart had to develop firmware
to support Watlow's gateway. "Although our equipment already
has software to manage, run, and operate the equipment and
to provide the customer with immediate feedback on the display,
we had to go a step further and communicate the proper data
and the proper format to the gateway," Mr. Cartwright explains.
Hobart will initially offer the gateway on some of its refrigeration
and warewashing appliances, although it plans to slowly add
compliance to other product lines. Specifically, the company
will launch its NAFEM-compliant blast chillers, LXi dishwashers,
and G, R, and A series Traulsen refrigerators and freezers
at the NAFEM trade show this month in New Orleans, LA, U.S.
According to Mr. Cartwright, Hobart's NAFEM-compliant equipment
can offer end users several benefits, including monitoring
temperature settings, product inventory, energy utilization,
and labor deployment.
At the restaurant chain level, a manager could, for example,
instantly retrieve chilling and holding records from blast
chillers and refrigerators throughout the chain. Data from
all points of the kitchen operations would verify that standards
were being followed. Managers could also monitor in real-time
warewashers to ensure proper sanitizing temperatures or the
supply of sanitizing chemicals. They could also improve the
efficiency of how often and how much of a particular product
or ingredient to order based on real-time product inventory.
Benefits include greater food safety, product freshness,
and the savings associated with just-in-time inventory.
One of Hobart's greatest challenges, then, was to decide
just how much data„whether it be temperature, pressure, or
serial number information„it wanted to offer its end users. "When
you say you're NAFEM compliant, the protocol is not a one-size-fits-all
situation. Everybody is going to use bits and pieces of protocol.
You don't have to use all of it," notes Mr. Cartwright. "We
were concerned about making sure that we knew how much data
the customer wanted„what provided value to the end user.
You could overwhelm a customer with data. For us, it was
trying to make sure we didn't just provide them with data,
but with a solution that could give them the flexibility
to get the types of data that would make their job easier
and more efficient."
Hobart also wanted to keep data points limited to offer
its customers cost savings. "A gateway is only capable of
handling a fixed number of data points," says Mr. Cartwright. "The
problem is once you use all those up, you need additional
gateways. There's an economic issue involved. So you'd like
to be able to optimize that number [of data points] and make
it as big as possible. "
To answer the data question, Hobart's marketing team met
with some of its customers and attended industry presentations
and determined what types of data points made sense for its
Kitchen Gateway (pictured) is just one of the
company's NAFEM-compliance offerings. The company
also offers the N7 food equipment controller
for equipment that needs advanced machine control
as well as connectivity.
Although each product is different and can be customized,
Hobart believes most of its customers will probably be most
interested in monitoring temperature for food safety reasons
as well preventative maintenance data.
The company's blast chiller, for example, can monitor temperature
via its product probes. According to Mr. Cartwright, the
monitoring process starts with Hobart's internal electronics,
which have the ability to read analog values from a sensor
that can measure temperature. "Coming from the front end,
you have a sensor, which in this case is a thermistor, and
then we feed that into an a-to-d converter and into a microcontroller," he
explains. "On the other end, we have a display so that we
can actually display that information to the customer. Then
we have the serial port that goes out to allow this data
to communicate to the Watlow gateway,
which in turn is attached to the kitchen network and uses
the NAFEM protocol to communicate data."
In the end, the equipment operator can access temperature
information from the product probes as well as temperatures
of the inside of the cavity or the coil for service reasons.
The key to making its compliant successful will be education,
according to Mr. Cartwright. "From a protocol standpoint,
the big challenge right now is just education„helping people
understand what it can do for them and the benefits," he
says. "It's a little different than some marketing scenarios
because we have a few customers that really demanded and
expected this, and then we're trying to go out to the masses
and help them understand why these other folks wanted it
and what it can do for them. It's not just for restaurant
Although it is anxious to see how customers react to its
products, Hobart already has design improvements in the works
to offer end users even more options. "Our equipment has
Flash memory, so you can flash them with updates. Ultimately,
we want to be able to do that remotely," says Mr. Cartwright. "The
protocol allows for that. We just have to work out the details.
There's some challenges there that not everyone can see.
It's not something that will be there at first, but it will
be there quickly."
Designing advanced electronics is nothing new for Hobart.
The manufacturer is used to doing its electronics design
from the ground up, making its partnership with Watlow an
exception to the way it typically designs its products.
"Although we use different companies to actually manufacture
our circuit boards, we design and specify all of our sensors,
controls, microprocessors, and write all the firmware. Using
an outside resource for the gateway is a deviation for us," Mr.
Cartwright says. "We felt like for the time constraints involvedƒit
was advantageous for us to use a solution from a source that
already had finished it. It was a much lower risk and much
faster. We felt Watlow had the knowledge and the talent to
support what we were trying to do."