OFF
OFF
S2
ONOFF
ON
bps 9600 38400
S1
Baud Rate Settings (S1 –S2 in SW3)
OFF
57600 115200
ON
ON
6. Tighten the screws until the wire is securely fastened in the slot.
7. If you removed the green connector in step 3, push the green
connector into the appropriate socket until it locks into place. The
connector and socket are keyed, so there is only one way to plug it in.
8. Reconnect the system power by first connecting the AC power
connector, then connecting the standby battery connector.
Wiring the Board
Insert wires into
green connectors
Before installing the SNIB3, you must first set the required DIP switches on the three switch banks:
OFF
ON
Switch Bank 1 (SW1)
This SNIB3 is either first (master) or last (termination) in the multidrop
sequence.
This SNIB3 is in the middle of a multidrop sequence.
S1 - 4
Setting the Board’s DIP Switches
OFF
ON
Switch Bank 2 (SW2)
This SNIB3 communicates with the host PC using the encryption keys stored in
memory.
Return the encryption keys to their default settings. If this switch is set when
the SNIB3 powers up or reboots after a firmware upgrade, the keys reset. This
switch can be turned off after the LED patterns begin to light. See the
DIGI*TRAC Design and Installation Guide. If this is the master SNIB3, you
must also ‘Reset Encryption’ on the Velocity Port settings. All downstream
units must have their encryption keys reset as well. If this is a downstream
unit, the master SNIB3 automatically detects that the keys have been reset.
S1
OFF
Normal operation. (ON only when resetting to factory defaults.)
This SNIB3 is NOT first in the multidrop sequence, or you only have one
controller.
S2 - 3 OFF
S4
ON This SNIB3 is first in the sequence (master) and is connected to the host via
Ethernet. This SNIB3 controls polling. A SNIB3 must be the master.
Baud rates only apply to the SNIB3’s RS-485 port. The SNIB3’s Ethernet port is used for host-to-
controller connections and runs at 10/100/1000 BaseT speeds. All SNIB2s and SNIB3s in a mixed
RS-485 multi-drop sequence must be set to the same speed. For example, if one SNIB2 in a mixed
sequence is set to 9600, all other SNIB2s and SNIB3s must be set to the same baud rate.
If you plan to multidrop SNIB2s and SNIB3s, the cable between the first (Master)
controller and the second must be wired as shown here:
RX- to TX-
RX+ to TX+
TX- to RX-
TX+ to RX+
Ground
Subsequent controllers on the same chain are wired point-to-point.
Address 1 Address 2
Master SNIB3 Subordinate SNIB3/SNIB2
This controls the baud rate for the RS-485 multi-drop
line. 57600 and 115200 bps are only available if your
RS-485 cables are made from Cat5 or Cat6 data grade
wire. These speeds are NOT recommended for
installations using:
· 18- to 22-gauge shielded twisted-pair cable
· NET*MUX4s
To use the SNIB3, your controller needs
CCM firmware version 7.5.37 or higher.
Standard Cable
SNIB3 RS-485 installations with standard 18-,
20-, and 22-gauge shielded twisted-pair cable
should use 9600 or 38400 bps. Do not use
higher speeds unless using Cat5 or Cat6 cable.
If you have communication problems at 38400
bps, reduce it to 9600 bps. Installations with
NET*MUX4s are limited to 9600 bps.
Cat5 / Cat6 Cable
For new SNIB3-to-SNIB3 RS-485 installations,
we recommend making your cables with Cat5/
Cat6, or equivalent grade cable to the appropriate
5-pin green connectors. Pick one color wire, such
as brown, to use for Ground. Distances up to
4,000 feet can be achieved with the RS-485
cabling type. If there is no NET*MUX4
involved, use 57600 or 115200 bps.
Communications become less robust as baud rates increase, wire gauge decreases,
and distances increase. Most tables in the DIGI*TRAC Design and Installation Guide
for wire gauge and distance are based on 9600 baud. At higher baud rates, maximum
distances are decreased and minimum wire gauge is increased. It may not be possible
to implement the higher baud rates supported by the SNIB2 or the SNIB3 if you have
long wire runs or small wire gauges. Higher baud rates are also more dependent on
the number of twists per foot, so capacitance specifications must be strictly followed:
total wire run per port is not to exceed 100,000 pf per foot.
To connect RS-485 serial cables between SNIB3s:
1. Turn all system power off by first removing the connector for the standby battery, then
disconnect the AC power connector or the power supply fuse.
2. Punch out the knockout in the controller enclosure where you plan to route the RS-485 cable.
You can either route this wire through the same opening you’re using for controller board
connections, or knock out a new opening.
3. Route the wires through the opening. If it makes serial wiring easier, detach each green connector
from the board as needed.
4. Loosen the screws on each RS-485 connector plug you will be using.
5. Remove insulation from the wire and insert the specified wires into the green connectors at the
required slots as shown to the right.
CCM and SNIB3 Firmware Upgrade Path:
· Upgrade CCM firmware and physically replace a SNIB2 with a SNIB3: Upgrade CCM first, then
switch from a SNIB2 to a SNIB3.
· Upgrade the CCM firmware and either physically replace a SNIB3 with another SNIB3 OR upgrade
SNIB3 firmware: It doesn’t matter which you upgrade first.
Firmware Download Rules:
· Do not download CCM and SNIB3 firmware simultaneously on the same port.
· Do not download CCM or SNIB3 firmware to the master SNIB3 at the same time as downstream
units on the same port. Upgrade the master before upgrading each downstream, one unit at a time.
· Do not download firmware to more than one downstream CCM or downstream SNIB2s on the same
port at the same time. The firmware download time multiplies with each additional controller
downloading. 3
2
The master must
be a SNIB3
To use the SNIB3, you must have
Velocity version 3.6 SP1 or higher.
