Programmer Owner manual
252
IQ
®
Programmer Reference Manual
ARP Tables - The Ghost in the Machine
ARP, which stands for “Address Resolution Protocol”, is a low-level router function that enables trafc to be correctly routed on the
Ethernet network. It is handled automatically by the router and is normally transparent to the user.
All network devices need to have two things: a MAC ID and an IP address.
• The MAC ID is a unique identier that is assigned to the chip on the network interface device. You can think of it as a
network serial number.
• The IP address is just that - an address. Like a street address on your house. IP addresses can be changed - MAC ID’s
cannot.
The following diagram shows a basic network. Note that each device has both a MAC ID and IP address. The router maintains
an ARP table, which is really just a list that matches MAC ID’s to IP addresses. An entry is created for every device on the
network.
It should be noted that computers maintain a local ARP table as well, tracking other devices they’ve interacted with. This is an
important point because the ARP table on a PC will typically refresh more frequently than those on a network router or switch.
So why do we care? Your application will probably require changing the IP address of a drive. The ARP table must then be
refreshed to show the same MAC ID with a different IP address. This is usually not an issue if the drive is directly connected to the
PC used to congure it, because the local ARP table will likely refresh quickly enough to catch the new IP address and re-establish
a connection.
The problem comes when the drive is connected through a router during conguration. In this scenario it is entirely possible for IP
address changes to happen more frequently than the ARP table can refresh itself. Most routers do not allow users to refresh the
ARP table directly, as this poses a signicant network security risk. The router must actually be rebooted to force a reset of the
ARP table and allow a connection with the new IP address. Obviously this is not an ideal solution.
For this reason we recommend that all conguration be performed while directly connected to a PC. Do not use a router for drive
conguration. Once an IP address is assigned the drive may be placed on the plant network without worry.
NOTE: If you nd that you are changing IP addresses often and the connection becomes unreliable, it may be
necessary to force a refresh of your PC’s local ARP table. This can be accomplished by opening a command window
and using the command arp -d. You must have administrator privileges on your PC to do this.
Conguring Your Drive
Three Windows programs are available from Bimba for use with our Ethernet/IP drives. These programs are the most recent
version is always available at www.bimba.com.
Bimba IQ
®
Stepper is used to congure your stepper drive and motor. It can also be used to change the selection of drive IP
addresses. IQ
®
Stepper includes extensive built-in help screens and manuals.
MAC ID: 08:A4:C3:10:0E:00
IP: 192.168.1.100
MAC ID: A2:FB:3D:21:7A:01
IP: 192.168.1.101
B-
B+
A-
A+
V-
V+
B-
B+
A-
A+
V-
V+
LED Codes
GR=Green
RD=Red
MOTOR DISABLED SOLID GREEN
MOTOR ENABLED GR-GR-GR
MOTOR STALL 1 GR + 1 RD
CCW LIMIT 1 GR + 2 RD
CW LIMIT 2 GR + 2 RD
CAN’T MOVE (DISABLED) 2 GR + 1 RD
DRIVE OVER TEMP 1 GR + 3 RD
VOLTAGE HIGH 1 GR + 4 RD
VOLTAGE LOW 2 GR + 4 RD
OVER CURRENT 1 GR + 5 RD
MOTOR OHMS 2 GR + 5 RD
OPEN MOTOR PHASE 1 GR + 6 RD
BAD ENCODER SIGNAL 2 GR + 6 RD
COMM ERROR 1 GR + 7 RD
GND
+5V OUT
Y COMMON
Y3 / FAULT
Y2 / MOTION
Y1 / BRAKE
X8 / CCWLIMIT+
X8 / CCWLIMIT -
X7 / CWLIMIT -
X7 / CWLIMIT+
Y4 -
Y4+
25
24
23
22
21
20
19
18
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
X COMMON
X3 / ENABLE
X5 / CWJOG
X4 / ALARM RESET
ANALOG IN2
ANALOG IN1
X2 / DIR -
X2 / DIR+
X1 / STEP+
X1 / STEP -
GND
X6 / CCWJOG
Serial No
ST5-Q
STEP MOTOR
DRIVER
MAC ID: 03:C8:11:2B:DE:02
IP: 192.168.1.102
ARP TABLE
MAC ID: 08:A4:C3:10:0E:00 <--> IP: 192.168.1.100
MAC ID: A2:FB:3D:21:7A:01 <--> IP: 192.168.1.101
MAC ID: 03:C8:11:2B:DE:02 <--> IP: 192.168.1.102