Electro-Voice 1252 - Manual (Page 126)

Electro Industries/GaugeTech Doc # E107706 V1.25 9-14
9.8.2: Communication
Q Maximum registers per request, read or write, is 4 registers.orm
Q The device will operate with the following Default Mode Parameters. See section 9.4.1 for details.
Address 247 (F7H)
Baud Rate 57600 Baud
Transmit Delay Time 20 csec
9.8.3: Normal Mode
Q Energy readings are given to the device frequently. The device generates a pulse at each channel
after a certain energy increase.
Q 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 difference 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 Rollover 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 Residual by the
Programmed Energy/Pulse Value. If the Residual is greater than the Programmed Energy/Pulse
Value and the Pending Pulses Value for that channel is not maxed, then Residual is decremented
appropriately and the Pending Pulses is incremented by two, signifying two more transitions and
one more pulse.
3. The third process runs from a timer which counts off pulse widths from the Programmable
Minimum Pulse Width Values. If there are Pulses Pending for a channel and the delay has
passed, then the Pulses Pending is decremented for that channel and the Output Relay is toggled.
Q Operation Indicator (0000H = OK, 1000H = Problem):
Bit 1: 1 = EEPROM Failure
Bit 2: 1 = Checksum for Communications Settings bad
Bit 3: 1 = Checksum for Programmable Settings bad
Bit 4: 1 = 1 or mor Communications Settings are invalid
Bit 5: 1 = 1 or more Programmable Settings are invalid
Bit 6: 1 = 1 or more Programmable Settings have been modified
Bit 7: 1 = Forced Default by Reset Value
Bit 15: 1 = Normal Operation of the device is disabled