Motion MMI-8S - Manual (Page 8)

HARDWARE DESCRIPTION
The MMI network control contains two CY233 SR4 cards, generally refered to as #0 and #1 which
is their binary address. Each card controls four SMC motor systems and includes status LEDs
and jumber posts (dip-clips) for setting its ID number. The cards are mounted to a single rail and
can be removed as a single unit as required during service.
Note: Do not attempt any procedure or remove any screws other than instructed; no user service
is possible to the interior assemblies!
SERVICE ACCESS
Remove the top cover (see following procedure) and access the interior of the MMI only: (1) to
adjust the motor current (factory preset to 1 amp/coil); (2) to set the network address clips
(factory preset to #0 & #1); (3) to observe the network LED displays during programming; as
required.
TOP COVER REMOVAL PROCEDURE
(1)
Remove only the four (4) corner 6/32 slotted-head screws holding the black,
top, cover; the cover edges will be retained by the front and rear panels.
(2) Pressing against the rear portion of the cover, at the raised bevel, with the thumbs,
slide the cover fully forward while keeping the cover edge under the lip of the front
panel. The rear lip of the cover will be exposed. Do not attempt to remove by sliding front
to rear.
(3)
Using care not to bend the cover, lift up both rear corners of the cover slightly
above the rear panel. Pull the cover towards the rear and lift off.
(4)
Replacement is the reverse of the above.
OPERATION
The CY233 microprocessor is used as an address controller for the multiplex system. When a
mode command, followed by a valid ID number, is received by the 233, the 233's address lines
select a multiplex channel. The remaining serial data (motion command string) is passed,
through the multiplexer, directly to the target device (motion system) until the detection of the
terminator charactor (carriage return) by the 233. After detecting the terminator, the 233 resets
the address lines and waits for the next mode command. If more than one controller is
connected to the serial network, invalid ID numbers and the serial data string are echoed to the
next controller down the line. If the ID is invaild for all controllers, the entire message will return
to the host CPU (echo invalid).
Note that contary to normal CY545 procedure, in a CY233 network system, all SMC motor control
commands MUST BE in LOWER case! All SR4 net commands must be in UPPER case! With that
said, it may be observed that the SMC's respond to upper case as well. Only during a query
responce will the SR4 repeaters strip off the upper case characters A to F which are seen as hex
control codes. This will not cause a malfunction but may be confusing to the user.