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Interfacing Party Mode Communications
2-14
Single Mode Communications Half Duplex (RS-485)
The MForce MicroDrive can be operated in a 2 wire RS-485 communication bus. Before connecting the 2 wire RS-485,
download your program and setup instructions using the standard 4 wire RS-422 Communications Cable. If a program
is not being used, download and save any setup parameters. To ensure the MForce MicroDrive responds only to com-
mands specifically meant for it, set the unit in Party Mode (Please see Party Mode below). The Echo Mode command
(EM) must be set to the value of 1 (EM=1). This will set the MForce MicroDrive communication into "half duplex"
mode. Connect the driver in the 2 wire RS-485 configuration. The following diagram illustrates how to connect the
MForce MicroDrive 4 wire RS-485 to operate as a 2 wire system.
2 Wire RS-485
Comm GND
Figure 2.3.2: Half Duplex 2 Wire Communications (RS-485)
In systems with multiple controllers it is necessary to communicate with the control modules using party mode
(PY=1). The MForce MicroDrive nodes in the system are configured in software for this mode of operation by
setting the Party Flag (PY) to True (1). It is necessary for all of the nodes in a system to have this configuration
selected. When operating in party mode, each MForce in the system will need a unique address, or name, to identify
it in the system. This is accomplished by using the software command DN, or Device Name. For example, to
set the name of an MForce to "A" you would use the following command: DN=65 or DN="A" (65 is the ASCII
decimal equivalent of uppercase A). The factory default name is "!". The asterisk character "*" is used to issue global
commands to every device in the system. NOTE: When using the asterisk "*" in Party Mode, typed entries and
commands will not be echoed. See Appendix A of the Software Reference for ASCII table.
In setting up your system for party operation, the most practical approach is to observe the following steps:
1.
Connect the first MForce MicroDrive to the Host PC configured for Single Mode Operation.
2.
Establish communications and download program if required.
3.
Using the command DN, name the MForce MicroDrive. This can be any upper or lower case ASCII character or
number 0-9. (DN="A"{enter}) (Note: The quotation marks before and after the device name are required.)
4.
Set the party flag PY=1{enter}.
5.
Press CTRL+J to activate the Party Mode.
6.
Type the letters AS and press CTRL+J (Save device name and Party Mode).
7.
Remove power.
8.
Repeat steps 1 through 7 for each additional MForce in the system.
9.
After all MForce MicroDrives are assigned a Device Name, the Multiple MForce Interface can be configured as
shown in the following figure.
Data Cable Termination Resistors
Data Cable lengths greater than 15 feet (4.5 meters) are susceptible to signal reflection and/or noise. IMS recommends
120 Ω termination resistors in series with 0.1µf capacitors at both ends of the Data Cables. An example of resistor place-
ment is shown in Figure 2.3.3. For systems with Data Cables 15 feet (4.5 meters) or less, the termination resistors are
generally not required.
B
A
Motion Control MForce MicroDrive Hardware Manual Revision R112706
2
MDrive34Plus/Plus
10-PIN IDC
10-PIN
FRICTION LOCK
WIRE CRIMP
CGND
Pin 10
Pin 2
RX-
Pin 4, 7
Pin 3, 8
RX+
Pin 3, 6
Pin 6, 7
Pin 2, 8
Pin 4,10
TX-
Pin 1, 9
Pin 1, 9
TX+
100Ω
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