ENDEVCO MODEL 136 DC AMPLIFIER
INSTRUCTION MANUAL
IM136
Page 28
1) The order of these items is fixed. For Model 133 the order is Input Select to Monitoring, for
Model 136 the order is Voltage Excitation to Monitoring. For the range of possible settings for
each item see the sections below on model specific hardware control.
2) Only complete setups are accepted (all 7 items sent even if only 1 changes).
3) Each item’s setting must be converted to a decimal integer string scaled to accommodate the
transmission of floating point values with resolutions to 1/1000. (ie all item settings are multiplied
by 1000 and converted to ASCII).
4) Each item is separated by 1 space character (0x20)
Channel Calibration Constant Data - This packet consists of 7 items. These items correspond exactly to
the 7 items associated with the Function LEDs on the front panel of the 13x units while in Calibration
Mode. The specifics of these are detailed in the section specifying Calibration Mode. Their method of
transmission is identical to that of the channel setup transmission.
Data Interval - This is an unsigned integer value (16 bits) which represents the number of seconds
between data transmissions, calibrated or raw, after either of the ‘Send Data’ commands is sent to a 13x
unit. A value of 0 indicates a single sample of data is requested. The 13x firmware will terminate the Send
Data condition after 1 sample of data (per enabled channel) is sent. To accomplish single transmissions
easily set the Data Interval to 0 first then send Send Data commands at will. One data sample per Send
Data command will be returned with this scenario. The firmware default is 0 - Single Shot mode.
Checksum (Required) A one byte summation of the entire transmission, header and data (if any) without
the terminator, is required on all transmissions sent to the 13x.
Terminator (Required) The last item in the transmission, A Line Feed character (0x0A).
Response (Required) The following table illustrates the response to the received command and the error
responses;
Command #
Command
13x Response
0x00
Setup to 13x
ACK
0x01
Cal Constants to 13x
ACK
0x02
Setup from 13x
Cmd <data>
0x03
Cal Constants from 13x
Cmd <data>
0x04
Calibrated Vout data
ACK ....Cmd <data>
0x05
Raw Vout data
ACK ....Cmd <data>
0x06
Stop Data
ACK
0x07
Data Interval to 13x
ACK
0x08
Reset Unit
ACK
0x09
Unit ID from 13x
Cmd <data>
0x0A
LP Corners from 13x
Cmd <data>
0x0B
Error List from 13x
Cmd <data>
0x0C
ACK
Reason
13x Error Responses
0x0D
Bad CS or Not enough data
NAK
0x0E
Channel # too high
Bad Channel
0x0F
Setup value out of range
Bad Setup
0x10
Hw setup unit reports error
Setup Error
0x11
Setup value out of range
Bad Cal Constant