KEP MMI-1 Series, Инструкции по эксплуатации и монтажу

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3.5 Using the Up and Down Arrow keys
(MMI-110 &140 Only)
The Up and Down Arrow keys on the MMI-110 & 140 are used to step up
or down through a preprogrammed list of messages. The list may be
called up by the PLC or by pressing a Function key. The message will stay
on the display until a new message is called by the MTR, Function Key
press or one of the arrow keys is pressed. When the top of the list is
reached the up arrow is ignored. When the bottom of the list is reached the
next message called by the down arrow will be the top of the list.
3.6 MMI Response
The MMI is limited in its response to key presses and information update by the serial
communications to the PLC. The MMI has been optimized to provide reasonable response times to
events.
3.6.1 Response Time to Message Calls
A message number must be in the MTR for at least 300 milliseconds to be recognized by the MMI.
3.6.2 Response Time to Function Key Presses
Function keys are handled on an interrupt basis. As soon as a key is pressed a communication is
sent to the PLC. Response to a key press by the PLC depends on the PLC’s scan time and
communications handling. Typically, response times are less than 1 second. We do not recommend
using the function keys for JOGGING applications.
3.6.3 Response Time to Serial Port Transmissions
When a called message has the attribute to be sent to the serial port, the MMI-1XX will send the
message to the port before displaying it. Response time is determined by the number of registers/bits
embedded in the message. The serial port baudrate also determines how long it will be before the
message is displayed. A 200 character scrolling message with several embedded registers and bits
sent out at 300 baud may take up to 10 seconds to appear on the display.