VIEW ALL TECH THREADS
By Jeff Payne
Product Manager, Automation Controls
Q: What are key differences
between the P3-530 vs. the
Image 1: CPU modules
A: Cost is the key reason to select a P3-530
vs. a P3-550 CPU. The P3-550 doews have
distinctive advantages in advanced features,
as shown in Table 1 on the next page. But
in many case the 530's features are more
than adequate. (Image 1) The two CPUs
program exactly the same1.
Q: What is the difference between remote
I/O and expansion I/O?
A: The primary difference between
remote I/O and expansion I/O is the distance
of the I/O from the CPU base, and
cost. The P3-EX (expansion I/O module) is
connected to the CPU via a 2 meter USB
cable. The P3-RS and P3-RX (remote slave
modules) are connected to the CPU via
a 10/100 Ethernet connection and the
distance from the CPU is subject to
Ethernet standards (~100 meters). Table
2 on the next page gives a more complete
comparison. (Table 2 & Image 2)
Image 2: I/O Modules
Q: Are there any I/O module restrictions
with the remote I/O and expansion I/O?
A: No, the Productivity3000 system
was designed to allow any module to be
placed in any slot of any base, regardless
of whether it's a local CPU base, expansion
I/O base or remote I/O base.
Image 3: Local and Remote I/O
Q: What is the maximum number of
remote I/O and expansion I/O bases I
can add to one CPU?
A: You can add up to 32 Ethernet
remote I/O bases to one CPU. Each of
these is called a "Base Group". So you can
have a total of 33 Base Groups (1 CPU +
32 remote = 33 Base Groups). Each Base
Group can have up to 4 additional USB
expansion bases for a total of 165 possiblebases
Q: Can the GS series and DURApulse
drives be connected to the
A: Yes, and this combination offers
many benefits to the user that are not
achievable with any other controllers
By using the GS-EDRV100 Ethernet
to serial interface card (required for this
configuration), you can connect the drives
directly to the Ethernet remote I/O network
of the P3-550 CPU. This allows the user
to not only auto-discover the drives once
connected to the network, but you can also
configure all drive parameters through the
Productivity Suite programming software
and choose to store these parameters with
the controller project. The benefit of this is when a drive is replaced in the field, all
configuration parameters are then reloaded
into the new drive automatically, drastically
Additional benefits include the use
of the GS Drive Read (GSR) and GS
Drive Write (GSW) instructions, which
greatly simplify the drive's communications
Image 4: Drives on Ethernet I/O Network
Q: How can I keep my rung length shorter
so I can see my entire ladder logic?
A: There are new options that allow
you to configure your ladder, tag names and
comments to better optimize your viewing
area. These include 'Wrap Tag Name' which allows you to set the maximum number of
characters in a line before the tag name
wraps to another line. There is also an
'Optimize Rung Lengths' that will remove
rung "white space" or empty columns that
exceed column 11. *Requires Productivity
Suite version 220.127.116.11 or later.
(Images 5 & 6)
Image 5: New options for configuring your ladder, tag names and comments for better
optimization of your viewing area.
Image 6: 'Wrap Tag Name' allows you to set the maximum number of
characters in a line before the tag name wraps to another line.
Q: Can you log data with both the P3-550
and P3-530 CPUs?
A: Yes, both CPUs have the USB
data port that allows you to connect a
Pen Drive style USB memory device and
record application data using a simple
utility within the software.
Q: Is it possible to access data log files
A: Yes, both the P3-550 and P3-530
CPUs have an integrated Web server that
allows you to access
data log files residing
on the memory
drive that is connected
to the CPU's
USB data port from a Web browser. The
web server also lets you view system tags,
and system event and error history.
Q: What is the benefit of a Tag name
A: Documentation and time. In most
all practical projects, the programmer is
required to document the program for
troubleshooting measures. With a Tag
name based controller you eliminate a step
in this process because each instruction
address is a descriptive tag.
Not only are you eliminating a
documentation step in the controller
process, but if your application also calls
for an operator interface panel, PC base
HMI, SCADA package or other business
system interface software,
you have greatly reduced the development
time in the overall schedule because
of the ability to share the tag databases.
This eliminates a huge step in any
Q: What is the benefit of having
multiple Ethernet ports on the CPU?
A: A common design flaw in
networking programmable controllers
is mixing I/O traffic and network traffic.
The P3-550 CPU has a dedicated "Internal"
Ethernet Remote I/O port that is different
from the "External" Networking Ethernet
port. Having these dedicated ports allows
the processor to prioritize scan-based tasks
and asynchronous tasks while reducing the
risk of network collisions on your critical
Table 1: Productivity3000 CPU comparison matrix
Table 2: Productivity3000 remote and expansion comparison matrix
1 The only instruction not supported by the
P3-530 is the LCD instruction. Also, the P3-530's
total I/O density is more limited because it only supports
expansion I/O and not remote I/O.
2 Only applies to the P3-550 CPU. The P3-530 CPU only supports expansion bases.