Electro Industries/GaugeTech Nexus 1262, Руководство пользователя

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Doc# E151701 9-15
9: External I/O Modules
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9.8.2: Communication
Maximum registers per request, read or write, is 4 registers.
The device will operate with the following Default Mode Parameters. See Section 9.4
for details.
Address: 247 (F7H)
Baud Rate: 57600 Baud
Transmit Delay Time: 20 ms
9.8.3: Normal Mode
Energy readings are given to the device frequently. The device generates a pulse at
each channel after a certain energy increase.
Normal Operation consists of three processes:
1. The first process accepts writes to registers 04097 - 04112. Writes can be up to
four registers long and should end on the fourth register of a group (register
04100, or registers 04103-04112 or registers 04109-04112). These writes can be
interpreted as two-byte, four-byte, six-byte or eight-byte energy readings. The
reception of the first value for a given channel provides the initial value for that
channel. Subsequent writes will increment the Residual for that channel by the dif-
ference of the old value and the new value. The previous value is then replaced
with the new value. Attempting to write a value greater than the programmed Roll-
over Value for a given channel is completely ignored and no registers are modified.
If the difference is greater than half of the programmed Rollover Value for a given
channel, the write does not increment the Residual but does update the Last Value.
Overflow of the Residual is not prevented.
2. The second process occurs in the main loop and attempts to decrement the Resid-
ual by the Programmed Energy/Pulse Value. If the Residual is greater than the Pro-
grammed Energy/Pulse Value and the Pending Pulses Value for that channel has not
reached the maximum limit, then Residual is decremented appropriately and the
Pending Pulses is increased by two, signifying two more transitions and one more
pulse.