MYERS EM Series User manual

114063D RS-232 User’s Manual
RS-232 Communications
“Series E / IE” and “Series EM”
Users Manual

114063D RS-232 User’s Manual
TABLE OF CONTENTS
Table of Contents ........................................................................................................................................... 2
Introduction .................................................................................................................................................... 3
Connection...................................................................................................................................................... 3
Terminal Settings ........................................................................................................................................... 4
Commands...................................................................................................................................................... 4
Shell Command .......................................................................................................................................... 4
Help screen................................................................................................................................................. 5
Version ....................................................................................................................................................... 5
Alarm Setpoint ........................................................................................................................................... 5
Meter Functions.......................................................................................................................................... 6
Status.......................................................................................................................................................... 6
Alarms........................................................................................................................................................ 7
Alarms, Events, and Tests Dump ............................................................................................................... 8
Date and Time ...........................................................................................................................................10
LOCATION OF THE RS232 PORT FOR “E” & “IE” 6-16.7k...................................................................11
LOCATION OF THE RS232 PORT FOR “E” & “IE” 1.5 –5.0k................................................................11
LOCATION OF THE RS232 PORT FOR “EM” 1.0 – 2.8k........................................................................12
The ZOOM Modem (Optional).....................................................................................................................15
Configuring the ZOOM Modem (optional)...............................................................................................15
Dialing the ZOOM Modem.......................................................................................................................15

114063D RS-232 User’s Manual
INTRODUCTION
This manual is intended to explain the operation of the serial communication protocol for the
“Series E”, “Series IE” and “Series EM” Emergency Lighting Central Inverter. Serial
Communication can be established by means of a computer using terminal emulation software
(such as Tera Term, PuTTy, xterm, etc.), or by any embedded device capable of RS-232 serial
communication. We shall call this device the Client.
The protocol used is proprietary, and specific to Myers “Series E”, “Series IE” and “Series EM”
Emergency Lighting Central Inverters.
CONNECTION
The Central Inverter has a 9-pin Sub-D (DB9) female connector typically located on the back
(inside) of the front display panel located on the door of the inverter. See below for the exact
location of the connector.
The connection between the Client and the Inverter is a straight-through connection.
Do not use a Null Modem Cable that flips pins 2 and 3.
Pin 2 and Pin 3 are the Data send and receive lines; Pin 5 is the Ground (common) line.
Optical isolation on the interface card provides galvanic isolation between the client device’s
ground signal and the inverter’s ground.
PC Connector DB-9 “E”, “IE” and “EM” Central Inverter
Connector DB-9
Straight Connection
Pins used = 2,3 5
Illustration 1 –Interconnect Schematic for RS-232 Connection

114063D RS-232 User’s Manual
TERMINAL SETTINGS
Baud Rate: 19,200
Data Bits: 8
Parity: None
Stop Bits: 1
Flow Control: None
Character Set: ANSI
The “Series E”, “Series IE” and “Series EM” RS-232 protocol uses carriage returns (‘\r’, ANSI
code 0x0D), but does not use line feeds (‘\n’, ANSI code 0x0A). If you are manually typing
commands, some terminal emulator software will automatically feed the line back when you press
enter (and a carriage return is sent) and when the inverter responds (with a response string
followed by a carriage return). However, some terminal emulator software will not do this, and you
will end up with something like the following which is difficult to read:
CMD> setpoint
lvac: 108.0 off
hvac: 132.0 off
nlbatt: 111.0 off
lb
att: 105.0 off
htemp: 45.0 off
lrc: 0.0 off
If this is the case, look for the setting in your terminal emulator software that automatically
appends line feeds after (outgoing or incoming) carriage returns.
When the inverter is not in ‘shell mode’, it will not echo back characters you type (even though it
is indeed receiving them). To see what you are typing when the inverter is not in ‘shell mode’, turn
on the ‘local echo’ setting on your terminal emulator.
When the inverter is in ‘shell mode’, it will echo back characters you type. You will want to turn
off the ‘local echo’ setting on your terminal emulator, or you will see doubles of every character as
you type.
*** Always use lower case letters for communication unless noted otherwise.***
COMMANDS
Shell Command
To be able to use the commands below, the inverter must be in ‘shell mode’. To enter ‘shell
mode’, simply type “shell” (without quotation marks) and press enter. If it doesn’t work, you might
have mistyped it, or the inverter may have received some characters before you even started. If
this is the case, just type “shell” again and press enter.
Remember that lower case letters must be used. Upper Case characters are ignored!
When in ‘shell mode’, the inverter will return a command prompt (CMD>) each time you press
enter. Once this command prompt (CMD>) appears, the inverter is ready to receive another
command.

114063D RS-232 User’s Manual
Help screen
You may type “help” at the command prompt for a listing of various commands available.
CMD>help
ver Display current firmware version.
set point Display or modify set points.
meter Display meter values.
status Display present status.
alarms Display alarms.
dump Dump logs (alarms, tests, events).
dt Display and change date-time setting.
help List shell commands with brief descriptions.
exit Exit from shell.
Version
The Revision level of the software is available by the “ver” command.
CMD>ver
IF: 2.08
FP: 1.02
CMD>
Alarm Setpoint
When the set point command is entered the following data is displayed:
CMD>setpoint
lvac : 108.0 off
hvac : 132.0 off
nlbatt: 111.0 off
lbatt : 105.0 off
htemp : 45.0 on
lrc :0.0 off
lvac is the Low Voltage AC alarm,
hvac is the High Voltage AC alarm,
nlbatt is the Near Low Battery Voltage alarm,
lbatt is the Low Battery Voltage Alarm,
htemp is the High temperature alarm set point, and
lrc is the Load Reduction Fault set point.
To change a setpoint, type ‘setpoint’, then press the ‘tab’ key, then the name of the setpoint
you wish to change, then press the ‘tab’ key again, then type the new value you wish to set, then

114063D RS-232 User’s Manual
press the ‘tab’ key once more, and type ‘on’ or ‘off’ (to turn the alarm on or off respectively) and
finally press ‘enter’.
For example, to turn on the low voltage alarm when the input voltage goes below 105 VAC, type
“lvac” and then press tab and type”105” and then tab and then type “on”and press enter.
CMD>setpoint lvac 105 on
The other set points can be changed in the same manner.
Meter Functions
To read Voltages and currents, the meter command may be used.
To use, type, “meter” and press enter. The following display will occur.
CMD>meter
vin : 118.3
vout : 118.3
iout : 12.3
vbatt : 54.1
ibatt : 0.1
tbatt : -61.1
tint : 29.8
imin : 0
days : 0
vaout : 1453.8
iwatts : 6.6
vin is the (utility side) input voltage to the inverter, in Volts.
vout is the output (load side) voltage of the inverter, in Volts.
iout is the output current of the inverter (current consumed by the load), in Amps.
vbatt is the voltage of the battery, in Volts.
ibatt is the current through the battery, in Amps.
tbatt is not currently supported in hardware. Ignore this value; for now it is meaningless.
tint is the ambient temperature inside the inverter cabinet, in degrees Celsius. To convert to
degrees Fahrenheit, subtract 32, then multiply by 5, then divide by 9. °𝐹 = 5(°𝐶−32)
9
imin is the cumulative ‘number of minutes’ (over its lifetime) that the inverter has spent running
on battery power.
days is the number of days that the inverter system has been running
vaout is the output power of the inverter, in Vars (VA –voltage ampere reactive).
iwatts is the power being provided by the battery, in Watts.
Status
The different statuses of the machine are accessible by typing “status” and enter.
The following message occurs when status command is sent:
CMD>status
Battery Power : 0
Battery Charging: 1
Line Present : 1
System Ready : 1

114063D RS-232 User’s Manual
In this example, the inverter is running on utility power, so the Battery Power status is 0 (false)
and Line Present is 1 (true). Battery Charging is 1 (true) because the battery will always
be charging, even when its full. When the battery is full, the inverter uses ‘float-charging’ to keep
the battery full –this only consumes a tiny amount of power (in the ‘meter’ example above, it is
shown consuming 6.6W as it float-charges). Finally, System Ready is 1 (true). This will always
be the case unless the inverter is rebooting, on battery power, or charging.
Alarms
The alarm status of the machine is available through the “alarms” command.
When the alarm command is typed, the following information is available.
CMD>alarms
Inverter : 0
Charger : 0
Output : 0
Overload : 0
Overload Shutdown: 0
High Ambient : 0
High VAC : 0
Low VAC : 0
Low Battery : 0
Near Low Battery : 0
Utility : 0
Load Reduction : 0
Runtime : 0
Circuit Breaker : 0
Overtemp : 0
The format is binary. A “1” indicates that the alarm is present (asserted); a “0” indicates that no
alarm is present (unasserted).
The Inverter alarm indicates a problem in the inverter’s internal circuitry.
The Charger alarm indicates a problem in the charging circuitry that charges the battery.
The Output alarm indicates an issue with the output, such as a short circuit.
The Overload alarm indicates too much load (above the rating of the inverter) on the output.
The Overload Shutdown alarm indicates that the load is so high (above the rating of the
inverter) that the inverter has shutdown to protect itself.
The High Ambient alarm indicates excessively high temperature inside the inverter cabinet.
The High VAC alarm indicates an excessively high input voltage (utility) to the inverter.
The Low VAC alarm indicates an excessively low input voltage (utility) to the inverter.
The Low Battery alarm indicates that the battery charge has almost been depleted.
The Near Low Battery alarm indicates that the inverter is approaching low battery.
The Utility alarm is 0 if the input voltage to the inverter is good, or 1 if it is not (indicating that
the inverter is currently running the output from the battery).
The Load Reduction alarm indicates a reduction in the load below a preprogrammed
threshold (which may happen if a load device goes offline, such as a lamp out). This feature is
turned off by default.
The Runtime alarm indicates a self-test has failed (perhaps due to the age of the battery).
The Circuit Breaker alarm indicates that a circuit breaker has tripped. This feature only
works when the right circuit breaker option is purchased.
The Overtemp alarm indicates that the internal circuitry of the inverter has reached an excessive
temperature.

114063D RS-232 User’s Manual
Alarms, Events, and Tests Dump
The dump command displays all of the memory content for Events, Tests or Alarms.
The dump command must be followed by a tab and then either “alarms”, “tests”or “events”as the
second field. After pressing the ‘enter’ key, the inverter will display a “Press Enter when ready…”
prompt. Press the ‘enter’ key once again, and the inverter will dump out the specified log. Note
that this log may be several kilobytes in size, and will be streamed out in one go.
Here is an abbreviated example of an alarm log dump:
CMD>dump alarms
Final settings will be displayed next.
If you wish to save to a file, enable text capture now.
Do not forget to stop capture after data is transferred.
Press Enter when ready...
***********< ALARM LOGS >***********
1/75 UTILITY
09/20/19 17:49
END : 09/20/19 17:49
2/75 UTILITY
02/11/19 12:52
END : 02/11/19 12:52
3/75 UTILITY
11/29/18 13:36
END : 11/29/18 13:36
4/75 UTILITY
09/11/18 12:41
END : 09/11/18 12:54
: : : :
74/75 LOAD REDUCTION
07/25/16 13:58
END : 07/25/16 13:58
75/75 LOAD REDUCTION
07/25/16 13:58
END : 07/25/16 13:58
CMD>
The alarm log has up to 75 entries, and in this example, it is full. The alarms shown above include
UTILITY alarms and LOAD REDUCTION alarms (see the write-up of the ‘alarms’ command
above for details on what these mean). The first date and time is the timestamp of the start of the
alarm event (when the alarm condition asserted), and the second date and time is the timestamp
of the end of the alarm event (when the alarm condition unasserted).

114063D RS-232 User’s Manual
Here is an abbreviated example of a test log dump:
CMD>dump tests
Final settings will be displayed next.
If you wish to save to a file, enable text capture now.
Do not forget to stop capture after data is transferred.
Press Enter when ready...
***********< TEST LOGS >***********
1/75 MONTHLY
09/20/19 17:43
DURATION : 5 MIN
FAULTS : 0
VOUT : 125.3
IOUT : 7.5
TEMP : 33.5 deg C
: : : :
75/75 MONTHLY
03/15/14 08:30
DURATION : 5 MIN
FAULTS : 0
VOUT : 126.2
IOUT : 6.4
TEMP : 26.3 deg C
CMD>
These log each of the times that the inverter ran self-test (which tests the battery and inverter
operation –the primary goal is to make sure that the battery does not yet need to be replaced).
Again, there is space for up to 75 logs. The first line of a log entry will indicate whether the self-
test was an automated monthly self-test (MONTHLY), or an automated yearly self-test (YEARLY). The
rest of the entry will tell you the timestamp of the self-test, the duration of the test (in minutes),
whether or not faults were detected, the output voltage (in Volts) and current (in Amps) of the
inverter during the test, and the ambient internal temperature inside the cabinet (in degrees
Celsius).
Finally, the event log (which also has up to 75 entries) will store the results of manually evoked
self-test events (EVENT). The entries will have the exact same format as the test log, but instead of
MONTHLY or YEARLY, it will say EVENT.

114063D RS-232 User’s Manual
Date and Time
The date and time can be viewed by typing the “dt” command.
When dt is sent, the interface sends back the date and time information. Each parameter of the
date and time are assigned a number. The dt command produces the following message:
CMD>dt
(1) day of week : 1..7
(2) month : 1..12
(3) day of month : 1..31
(4) year : 0..99
(5) hours : 0..23
(6) minutes : 0..59
THU OCT 10, 2019
14:59:24
CMD>
The number for the day of week parameter for example is 1 and its allowed values are 1
through 7, where 1=Sunday, 2=Monday, … , 7=Saturday.
To change a parameter, type the dt command, then press the ‘tab’ key, then type the parameter
number, press ‘tab’ again, then type the new value you wish to set the parameter to, and finally
press ‘enter’.
Note: The inverter does not support Daylight Savings Time. If you set the inverter date and time
during daylight savings, note that logged timestamps during non-daylight-saving times (i.e. winter)
will be one hour ahead of the actual time (because the actual time went back by an hour). Or, if
you set the inverter date and time during non-daylight-savings (i.e. winter), logged timestamps
during daylight saving times will be one hour behind the actual time (because the actual time
went forward by an hour). Alternatively, you can change the inverter’s date and time during the
switches into and out of daylight savings.